SVIBOR - Papers - project code: 1-08-070

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Published papers on project 1-08-070


Quoted papers: 15
Other papers: 29
Total: 44


  1. Type of paper: Paper in book

    Title: Specificity in RNA:protein interactions; the recognition of Escherichia coli glutamine tRNA

    Authors:
    Rogers, M.J.
    Weygand-Đurašević, Ivana (57696)
    Schwob, Etienne
    Sherman, J.M.
    Rogers, K.C.
    Thomann, H.U.
    Sylvers, L.A.
    Jahn, M.
    Inokuchi, H.
    Ohtsuka, Eiko
    Soll, Dieter
    Editors
    Nierhaus, K.H.
    Subramanian, A.R.
    Erdman, V.A.
    Franceschi, F.
    Wittman-Liebold, B.
    Publisher: Plenum press
    Year: 1993
    Pages: from 47 to 66
    Number of references: 33
    Language: engleski
    Summary: A variety of genetic, biochemical and structural studies havebeen used to determine factors ensuring the accuracy ofrecognition by aminoacyl-tRNA synthetases for tRNA. The identityelements of Escherichia coli tRNA(Gln) are located mainly in theanticodon and acceptor stem, and ensure the accurate recognitionof the tRNA by glutaminyl-tRNA synthetase. We summarize a numberof experimental tehniques to define the accuracy ofaminoacylation in vivo and in vitro.
    Keywords: aminoacyl-tRNA synthetases, tRNA

  2. Type of paper: Paper in book

    Title: Crick, Francis Harry Compton

    Authors:
    Kućan, Željko (24372)
    Editors
    Vince, R.
    Publisher: Biblioteka Hrvatski radio
    Year: 1994
    Pages: from 152 to 155
    Language: hrvatski

  3. Type of paper: Paper in book

    Title: Watson, James Dewey

    Authors:
    Kućan, Željko (24372)
    Editors
    Vince, R.
    Publisher: Biblioteka Hrvatski radio
    Year: 1994
    Pages: from 651 to 654
    Language: hrvatski

  4. Type of paper: Paper in book

    Title: My early days at the Rockefeller

    Authors:
    Kućan, Željko (24372)
    Editors
    Paar, Vladimir
    Publisher: Školska knjiga
    Year: 1995
    Pages: from 60 to 62
    Language: engleski

  5. Type of paper: Paper in journal

    Title:

    Authors:
    Kućan, Željko (24372)
    Journal: Filozofska istraĐivanja
    Volume: 15
    Year: 1995
    Pages: from 93 to 101
    Language: hrvatski

  6. Type of paper: Paper in journal

    Title:

    Authors:
    Kućan, Željko (24372)
    Journal: Encyclopaedia Moderna
    Volume: 14
    Year: 1993
    Pages: from 115 to 121
    Language: hrvatski

  7. Type of paper: Summary in proceedings

    Title: Complexes of yeast tyrosil-tRNA synthethase with tRNA

    Authors:
    Rubelj, Ivica (108443)
    Weygand-Đurašević, Ivana (57696)
    Kućan, Željko (24372)
    Proceedings title: 15th International Congress of Biochemistry
    Language: engleski
    Place: Jerusalem, Israel
    Year: 1991
    Pages: from 149 to 149
    Meeting: 15th International Congress of Biochemistry
    Held: from 08/04/91 to 08/08/91
    Summary: Yeast tyrosyl-tRNA synthethase (TyrRS) is an alpha2 enzyme ofthe subunit Mr=45000. Complexes of TyrRS with tRNA were studiedby polyacrylamide gel elektrophoresis. In the absence of ATP, twoA2-enzymes bind any cognate or noncognate tRNA molecule andprotect it efficiently against nuclease digestion. Competitionexperiments show that in the (alpha2)2-tRNA type of complex thebinding of tRNA(Tyr) is only 10-fold stronger than the bindingof non-cognate tRNAs. However, even the binding of non-cognatetRNA inhibits the pyrophosphate exchange rection on TyrRS. Excessof cognate tRNA(Tyr) and/or ATP prevents the binding ofnon-cognate tRNA and flavours the formation of alpha2-tRNA(Tyr)complex, in which the tRNA is only partially shielded againstnucleases. ATP can be replaced by GTP, a competetive inhibitor ofTyrRS, in the formation of the alpha2-tRNA complex, but not inthe aminoacylation reaction. The alpha2-enzyme, stabilized byATP, seems to be the only specific and catalytically active form.On the other hand, the (alpha2)2-form, as well as the alphasubunit alone, show very strong general affinity towards nucleicacids, but are completely devoid of specificity towards tRNA(Tyr)
    Keywords: tyrosyl-tRNA, electrophoresis, digestion,

  8. Type of paper: Summary in proceedings

    Title: The accurate recognition of Escherichia coli glutamine tRNA

    Authors:
    Rogers, M.J.
    Weygand-Đurašević, Ivana (57696)
    Schwob, Etienne
    Sherman, J.M.
    Rogers, K.C.
    Thomann, H.U.
    Sylvers, L.A.
    Jahn, M.
    Fett, R.
    Inokuchi, H.
    Ohtsuka, Eiko
    Soll, Dieter
    Editors
    Blanquet, S.
    Proceedings title: 15th International tRNA workshop
    Language: engleski
    Place: Cap d'Agde, Francuska
    Year: 1993
    Pages: from 144 to 144
    Meeting: 15th International tRNA workshop
    Held: from 05/30/93 to 06/04/93
    Summary: Genetic, Biochemical and biophysical tehniques have been used todefine the factors ensuring the accurate recognition by E.coliglutaminyl-tRNA synthethase (GlnRS) for its substrates: ATP,glutamine and tRNA(Gln). This has resulted in the first RNA:protein strukture determined by X-ray crystallography (1,2). Thaaccuracy of amiloacylation of the tRNA depends on two principles:competetion between synthetases in the cell (3,4), and therecognition of identity elements principally located in theanticodon and acceptor stem of tRNA(Gln) (5,6). The recognitionof individual nucleotides, as in interaction with the 2-aminogroup of G, is also apparent from studies withinosine-supstituted tRNAs (7). A genetic selection has beenfruitful in obtaining mutants of GlnRS which confer altered inacceptor stem recognition (8,9). As an extension of this, agenetic selection has been employed to isolate compensatingmutations in GlnRS that now aminoacylate (with glutamine) theopal suppressor derived from tRNA(Gln).The mutations in GlnRSwhich confer altered recognition of opal suppressor are locatedin two regions. One mutant altered in acceptor stem recognitionwas previously isolated by a genetic selection scheme using ambersuppressor tRNAs (8). The second type of mutation, suprisingly,alters a region that interacts with the inside of the L-shapedtRNA molecule, but was not implicated by the tRNA(Gln). GlnRSstructure as being important for specific recognition. Thisregion may provide a structural connection between the anticodonbinding domain and acceptor stem binding domain of GlnRS.Analysis of a number of mutations in this region isolated by acombination of in vitro mutagenesis and genetic selection revealsthe permutation of residues that modify the communication betweenanticodon and acceptor stem recognition in the glutamine system.
    Keywords: accurate recognition by E.coli glutaminyl-tRNA synthetases,

  9. Type of paper: Summary in proceedings

    Title: Transfer RNA recognition by Saccharomyces serevisiae seryl-tRNA synthetase

    Authors:
    Weygand-Đurašević, Ivana (57696)
    Soll, Dieter
    Editors
    Blanquet, S.
    Proceedings title: 15th International tRNA workshop
    Language: engleski
    Place: Cap d'Agde
    Year: 1993
    Pages: from 312 to 312
    Meeting: 15th International tRNA workshop
    Held: from 05/30/93 to 06/04/93
    Summary: Correct recognition of tRNAs by aminoacyl-tRNA synthetases is aprerequisite for accurate protein synthesis in the cell. In orderto elucidate how a eucaryotic class II synthetase specificallyrecognizes its cognate RNA substrates and discriminates againstnon-cognate tRNAs, we have focused our investigation onseryl-tRNA synthetases (SerRS) from S. cerevisiae. Its gene hasbeen cloned and sequenced (1) and can be functionally expressedboth in yeast and in E.coli. This gives us the advantage of usinga bacterial host for selected experiments. The functional complementation of two temperature sensitivemutations in the E.coli serS gene by S. cerevisiae serS showsthat yeast SerRS recognized and aminoacylates bacterial serinespecific tRNAs in vivo. The co-expression of two eucaryotic ambersuppressor tRNA genes, encoding either a human or aSchizosaccharomyces pombe tRNA(Ser), together with the yeastserS gene in a suitable E.coli host, resulted in suppression ofE. coli nonsense mutations. Such a recognition of procaryotic andheterologous eukaryotic serine specific tRNAs by yeast SerRSsuggests the conservation of at least some serine identityelements in evolution. E. coli-like yeast SerRS has been constructed by deletion of theregion encoding the unusual, positively charged 20 amino acidC-terminal extension in the eucaryotic protein. Our studies showthat this peptide is dispensable for the viability of the yeastcell.

  10. Type of paper: Summary in proceedings

    Title: Changes in gene expression in SV40 transformed human cells

    Authors:
    Rubelj, Ivica (108443)
    Pereira-Smith, O.M.
    Proceedings title: The Gerontologist
    Language: engleski
    Place: Washington, USA
    Year: 1992
    Pages: from 120 to 120
    Meeting: The Gerontological Society of America 45th Annual Scientific Meeting
    Held: from 11/18/92 to 11/22/92
    Summary: Normal human cells stably express the phenotype of limiteddivision (senescence) in vitro. Spontaneous imortalization hasnot been reported for these normal cells. However, theintroduction of DNA tumor viruses such as SV40 into human cellsresults in immortalization at a low frequency. It is establishedthat SV40 T ag alone is not sufficient to immortalize humancells and a second event involving cellular genes must occur. Toidentity the latter, we studied normal human diploidfibroblasts, IMR-90, transfected with SV40 in the stages ofprecrisis, crisis and prostcrisis. Northern blot analysis of cdc2indicated that this gene is overexpressed 2-3 fold in crisiscells. However, this was not reflected at the protein level.Fibronectin protein and RNA are at higher levels in cells incrisis whereas cyclin B protein and RNA are decreased. The SDI1coding gene coding for an inhibitor of RNA synthesis andoverexpressed in senescent cells also was overexpressed atcrisis. Flow cytrometric analysis indicates that cells in crisisaccumulate in the G1 phase of the cell cycle. These resultssuggest that gene regulation in cells in crisis resembles that ofsenescent cells in some cases but that T ag disrupts theregulation of other genes such as cdc2. (Supported by NIH grant2 PO1 AGO7123.)

  11. Type of paper: Summary in proceedings

    Title: Cloning the gene coding for cytoplasmic tyrosyl-synthetase from yeast

    Authors:
    Sever, Sanja (179365)
    Editors
    Schwienhorst, A.
    Lindermann, B.J.
    Proceedings title: Young perspectives on molecular biotechnology
    Language: engleski
    Place: Gottingen, Njemačka
    Year: 1992
    Pages: from 22 to 22
    Meeting: Young perspectives on molecular biotehnology First International Meeting
    Held: from 02/23/92 to 02/29/92
    Summary: Accuracy of translation of the genetic message depends on atleast two steps: correct aminoacylation of every specific tRNA,catalyzed by cognate aminoacyl-tRNA synthetase, and correctreading of each codon on the ribosome. Yeast tyrosyl-tRNA synthetase (TyrRS) is an alpha2 enzyme ofsubunit Mr=45000. TyrRS can interact both with cognate andnon-cognate tRNA which is in discrepancy with her biologicalfunction of specific aminoacylation of tRNA(Tyr). Complexes ofTyrRS with tRNA were studied by gel retardation assay. Two kindsof stable complexes were identified. The first complex has thecomposition tRNA(alpha2) and can be formed both with cognate andnon-cognate tRNA. The other complex has the complsition of tRNA(alpha2) and can beformed only with the cognate tRNA(Tyr). In other to determine theenzyme structure, a S. cerevisiae genomic expression library wasscreened with antibodies against TyrRS. In this way positiveclones which contain inserts of different size (o.2-5 kb) wereobtained. Southern blot show that seven of them cross hybridized.Based on amino acid sequence homology between known sequence ofTyrRS from different organisms degenerated pools ofoligonucleotides were used as primers for amplifyling the targetsequence. The amplifield sequence belongs to mitohondrial TyrRSand will be used as a probe in Southern blot in aim to conformhomology between clones obtained with antibodies. DNA sequencingof positive clones is in progress.

  12. Type of paper: Summary in proceedings

    Title: Tyrosyl-tRNA Synthetase from yeast

    Authors:
    Sever, Sanja (179365)
    Editors
    Putz, J.
    Dotsch, V.
    Proceedings title: Young scientist view of molecular biotechnology
    Language: engleski
    Place: Strasbourg, Francuska
    Year: 1993
    Pages: from 25 to 25
    Meeting: Young scientist view of molecular biotehnology 2nd International meeting
    Held: from 02/28/93 to 03/06/93
    Summary: Yeast tyrosyl-tRNA synthetase (TyrRS) is an alpha2 enzyme ofsubunit Mr=45000. TyrRS can interact both with cognate andnon-cognate tRNA which is in discrepancy with its biologicalfunction of specific aminoacylation. tRNA(Tyr) from E.coli is notaminoacylated by yeast TyrRS, and analysis of a number of mutantsas substrates for yeast TyrRS has led to identification of C1-G72base pair and discrimination base A73 conserved in all eucaryoticcytoplasmic tRNA(Tyr), as being important for recognition.Absolute requirement C1-G72 suggest that the yeast TyrRScontacts this base pare directly, and if so, this contact islikely to be in the major-groove side of the base pair as theenzymes belonging to the class II. However, from it is preferenceof aminoacylation at 2-OH over 3-OH, it would, like E. coli TyrRSseem to belong to class I. In order to determine the enzyme structure, a S. cerevisiaegenomic expression library were screened with antibodies againstTyrRS. Between nine positive clones that were obtained, sevenshare homology. Southern blot show that a positive clone containg4kb is expressed as fusion protein while another containing 5kbis expressed from late lambda promoters and internal translated.In order to sequence this two positive clones they were clonedinto the M13 vectors and sequenced using synthesizedoligonucleotide probes. The sequence determined from positivethat contain 4kb contains an open reading frame for 213C-terminal amino acid but the deduced amino acid sequence doesnot show strong homology with other TyrRS available sequences.Since the C-terminal part of the positive that contain 5kb inorder to determine the N-terminal part of the cloned gene.Sequencing is in progress.

  13. Type of paper: Summary in proceedings

    Title: Identification of the gene ror protein kinase from Saccharomyces cerevisiae

    Authors:
    Sever, Sanja (179365)
    Weygand-Đurašević, Ivana (57696)
    Walter, P.
    Fasiolo, F.
    Proceedings title: Godišnji sastanak hrvatskih biokemičara
    Language: engleski
    Place: Zagreb
    Year: 1993
    Pages: from 103 to 103
    Meeting: Godišnji sastanak hrvatskih biokemičara
    Held: from 06/17/93 to 06/18/93
    Summary: A 4kb yeast DNA fragment containing a putative TyrRS gene hasbeen recloned into the M13, mp18 and mp19 vectors and sequencedusing specially synthesized oligonucleotide primers. An openreding frame of 950 bp was found starting with AUG on theposition 900. Comparison of N-terminal protein sequence deducedfrom the DNA fragment with protein sequences in the Swissprotbank showed that a gene coding for a serine/threonine kinase wascloned. For the initial clasiffication of the novel proteinkinase we screened the catalytic domain database:genbank/EMBL/PIR. The new enzyme showed the higest homology withkinases from higher eucaryotes: mouse ribosomal protein S6kinase, human protein related to PhK-gama, rat calcium/calmodulindependent protein kinase II, ribosomal protein S6 kinase fromXenopus oocyte. Since only the N-terminal part of the enzyme thatposseses kinase catalytic domain was sequenced, addilationsequencing is necessary for correct clasification of the novelkinase.

  14. Type of paper: Summary in proceedings

    Title: Interaction of yeast tyrosyl-tRNA synthetase with ATP and tRNA(Tyr)

    Authors:
    Budiša, N.
    Rubelj, Ivica (108443)
    Katić, M.
    Kućan, Željko (24372)
    Proceedings title: Godišnji sastanak hrvatskih biokemičara
    Language: engleski
    Place: Zagreb
    Year: 1993
    Pages: from 111 to 111
    Meeting: Godišnji sastanak hrvatskih biokemičara
    Held: from 06/17/93 to 06/18/93
    Summary: Tyrosyl-tRNA synthetase (TyrRS) from Saccharomyces cerevisiae isan alpha2 enzyme (Mr=2*45000) with "half of site" activity.However, in addition to the specific cognate alpha2-tRNA(Tyr)complex, it forms unspecific (alpha2)2-tRNA complexes with lowestaffinity for TyrRS (Km==,32mM, compared with 8mikroM fortyrosine, 0,12mikroM for tRNA(Tyr) and Ki=0,3mikroM forperiodate-oxidized tRNA(Tyr) as a competetive inhibitor), wasfound to prevent formation of unspecific complexes. ATP is alsoan effective inhibitor at high concentrations (Kss=11mM).Obviously, the second binding site must be involved in theinhibition. It is likely that in the absence of tRNA the twoTyrRS subunits can simultaneously catalyze the first reactionstep. Namely, the k(cat) for pyrophosphate exchange (54 1/s,compared with 2 1/s for the over-all reaction) is substantiallylowered by the binding of tRNA. Hence, tRNA binding may reduceaccessibility of the second (or both) binding sites to the othertwo substrates. On the other hand, ATP binding to the second sitemay inhibit the over-all reaction either by changing theconformation of the acting active site, or by direct interferencewith the binding of the distant (i.e. anticodon) part of the tRNAto the other subunit.

  15. Type of paper: Summary in proceedings

    Title: Mutants of yeast seryl-tRNA synthetase in the proposed active site

    Authors:
    Weygand-Đurašević, Ivana (57696)
    Lenhard, Boris
    Landeka, Irena
    Soll, Dieter
    Proceedings title: 16th International tRNA workshop
    Language: engleski
    Place: Madison, Wisconsin, USA
    Year: 1995
    Pages: from 242 to 242
    Meeting: 16th International tRNA workshop
    Held: from 05/27/95 to 06/01/95
    Summary: Seryl-tRNA synthetase (SerRS) from Saccharomyces cerevisiae is a homodimeric class II aminoacyl-tRNA synthetase. It shares significant sequence homology with and has the same oligomeric structure as the SerRS enzymes from prokaryotic sources. In our search for active site of yeast SerRS , we have performed saturation in vitro mutagenesis of the portion of SES1 gene encoding the domain which studies on other class II synthetases have implicated as being important for the enzyme function. Eleven SerRS mutants, with amino acid substitutions at various positions between residues 281 and 297, have been obtained. The contribution of particular amino acid to the specificity of aminoacylation is being analyzed in vivo, by complementation of yeast SES1 null-allele strain and in vitro, after purification of the mutant SerRS enzymes from a yeast overproducing strain.
    Keywords: seryl-tRNA synthetase mutants

  16. Type of paper: Summary in proceedings

    Title: Transfer RNA recognition by class II synthetases

    Authors:
    Weygand-Đurašević, Ivana (57696)
    Editors
    Varljen, Jadranka
    Proceedings title: Godišnji sastanak hrvatskih biokemičara
    Language: engleski
    Place: Opatija
    Year: 1994
    Pages: from 15 to 15
    Meeting: Godišnji sastanak hrvatskih biokemičara
    Held: from 10/14/94 to 10/15/94
    Summary: Correct recognition of tRNAs by aminoacyl-tRNA synthetases is a prerequisite for accurate protein synthesis in the cell. This family of enyzmes can be divided into two classes, which differ in structure of their ATP binding site and in the mode of interaction with tRNA. In order to elucidate how an eukaryotic class II synthetase specifically recognizes its cognate RNA substrates and discriminates against non-cognate tRNAs, we have focused our investigation on seryl-tRNA synthetase (SerRS) from Saccharomyces serevisiae. Its gene SES1 has been cloned and sequenced and can be functionally expressed both in yeast and in Escherichia coli. This gives us the great advantage of combining genetic, biochemical and molecular biological approach in our studies. In order to investigate structure/function relationship in SerRS, a number of mutated forms of the enzyme has been generated by extensive in vitro mutagenesis of SES1 gene. Mutations were directed to the putative active site of SerRS, and to its unusual , positively charged C-terminal extension. In vivo characterization of the mutants have been achieved by complementation of yeast strain with disrupted SES1. We have also developed the methods for overproduction and purification of yeast SerRS and its mutants from E. coli and yeast , what assures a good source for kinetic analysis in vitro.
    Keywords: tRNA, seryl-tRNA synthetase, mutagenesis

  17. Type of paper: Summary in proceedings

    Title: Mutant forms of seryl-tRNA synthetases

    Authors:
    Landeka, Irena
    Lenhard, Boris
    Weygand-Đurašević, Ivana (57696)
    Editors
    Varljen, Jadranka
    Proceedings title: Godišnji sastanak hrvatskih biokemičara
    Language: engleski
    Place: Opatija
    Year: 1994
    Pages: from 73 to 73
    Meeting: Godišnji sastanak hrvatskih biokemičara
    Held: from 10/14/94 to 10/15/95
    Summary: The aminoacyl-tRNA synthetases play a crucial role in protein biosynthesis by specifically charging tRNAs with their cognate amino acids. This process of precise macromolecular recognition can be altered by introducing structural changes either into the synthetase or the tRNA. In our search for the active site of Saccharomyces cerevisiae seryl-tRNA synthetase (SerRS), we have performed in vitro mutagenesis of the portion of SES1 gene , which studies on other synthetases have implicated as being important for the enzyme function. Eleven SerRS mutants, with amino acid substitutions at various positions between residues 281 and 297, have been obtained. this domain is highky homologous between seryl-tRNA synthetases from different organisms. The contribution of different amino acid to the specificity of aminoacylation has been analyzed in vivo and in vitro. Yeast SerRS carries a C-terminal extension of 20 amino acids for wich there is no homology in the prokaryotic seryl-tRNA synthetases. This stretch is primarily composed of basic residues. To investigate the possible structural and functional role of this peptide, truncated enzyme has been generated by expression of of the deleted SES1 gene, constructed by loop-out mutagenesis with synthetic oligonucleotide. It retauned low level of aminoacylation activity and its thermal stability is much below the full-length protein. Our results show that the C-terminal fragment, although dispensable for the cell viability, as assayed by in vivo complementation, is important for integrating the overall structure of the protein.
    Keywords: seryl-tRNA synthetase, mutagenesis

  18. Type of paper: Summary in proceedings

    Title: Human versus bacteria: do bacteria win?

    Authors:
    Kućan, Željko (24372)
    Proceedings title: Dani Frane Petriša
    Language: hrvatski
    Place: Cres, Hrvatska
    Year: 1995
    Pages: from 27 to 29
    Meeting: Dani Frane Petriša
    Held: from 07/16/95 to 07/20/95

  19. Type of paper: Ph.D.

    Title: The activity and specificity of tyrosyl-tRNA synthetase from yeast of Saccharomyces cerevisiae
    Faculty: Prirodoslovno-matematički Zagreb
    Date of defense: 02/27/91
    Language: hrvatski
    Number of pages: 95
    Summary: Yeast tyrosyl-tRNA synthetase can interact both with cognate andnon-cognate tRNAs which is in discrepancy with her biologicalfunction of specific aminoacylation of tRNA(Tyr). To investigate the factors responsible for the specificity ofthe enzyme, retardation gel assay and enzyme kinetics were usedinteraction of TyrRS with DNA has been, also investigated byelectron microskopy. It has been found that ATP plays a crucial role in specificity ofthe enzyme and that 4 negative charges of phosphates arenecessary for such effect. No influence of tyrosine in theinteraction of TyrRS with tRNA has been observed. It has also, been found that a subunit of enzyme can bind bothcognate and non-cognate tRNAs, however for specific binding oftRNA(Tyr) both subunits are necessary. This supports ourassumption that tRNA(alpha2) represent functional complex in theaminoacylation reaction. TyrRS can also bind double strand DNA and longer chains of asingle strand DNA, but ATP has no influence in these interaction.The enzyme is bound within the double strand DNA chain. The elongated shape of TyrRS, revealed by electron microscopy,offers the explanation for the behavior of the complexes ingradient gel electrophoresis.
    Keywords: aminoacyl-tRNA synthetase, tRNA


  20. Type of paper: M.A.

    Title: Cloning the gene for cytoplasmic ryrosil-tRNA synthetase from yeast Saccharomyces cerevisiae
    Faculty: Prirodoslovno-matematički Zagreb
    Date of defense: 09/24/93
    Language: hrvatski
    Number of pages: 83
    Summary: The cytoplasmic tyrosyl-tRNA synthetase from yeast is ahomodimer (alfa2) with subunit molecular weight of 44000. Inother to clone the gene coding for cytoplasmic tyrosyl-tRNAsynthetase from yeast, S. cerevisiae genomic expression librarywas screened with antibodies against TyrRS. In this way ninepositive clones which contain inserts of different size (0.7-5kb) were obtained. Some of the clones were expressed as fusionproteins with B-galactosidase, while in others the whole proteinwas internally translated. Deduced amino acid sequence of a newprotein dose not show strong homology with other tyrosyl-tRNAsynthetases. Further analysis of the cloned yeast DNA (933bp), revealedanother open reading frame, carrying the information forN-terminal part of new protein kinase. The enzyme shows thehighest homology with kinases from higher eucaryotes: mouseribosomal protein S6 kinase, human protein related to PhK-gama,rat calcium/calmodulin dependent protein kinase II, ribosomalprotein S6 kinase from Xenopus oocyte, mouse, human and rat.
    Keywords: aminoacyl-tRNA synthetases, gene cloning, DNA sequencing


  21. Type of paper: M.A.

    Title: Specific spin labeling of DNA
    Faculty: Prirodoslovno-matematički Zagreb
    Date of defense: 07/03/91
    Language: hrvatski
    Number of pages: 72
    Summary: The possibility of sequence specific spin labeling of DNA hasbeen examined in this work. Three different spin probes andseveral DNA fragments from different sources, but of knownsequences, have been used to determine these effects. The lengthsof the breakage products of 5-end labeled DNA treated with spinlabels were compared with the length of DNA scission productsgenerated by Maxam-Gilbert procedure for DNA sequence analysis.Spin labeling was performed in the buffer containing 25 mMtriethanolamine HCl pH 7.2 and 1 mM EDTA. Spin labels I and II were able to modify the DNA. Themodification took place only at the N-7 guanine atoms. Fragment BamHI/Sall deriving from plasmid pBR322 wasspecifically spin labeled. The very limited amounts of spin probeII have selectively alkylated GGTGG sequence in the fragment. The influence of spermine and magnesium ions on specific spinlabeling has also been studied. In their presence, the level ofalkylation was decreased. The stabilization of DNA structure bymagnesium or spermine, directed the spin label specifically tothe DNA fragment containing GGTGG sequence. The frequency of alkylation by spin labels of the other fragmentsshowed preferential, but not exclusive reaction in the continousruns of guanines in DNA.
    Keywords: DNA labeling, spin probes


  22. Type of paper: M.A.

    Title: The screening of Saccharomyces cerevisiae genomic DNA library with antibodies against tyrosyl-tRNA synthetase
    Faculty: Prirodoslovno-matematički Zagreb
    Date of defense: 07/05/92
    Number of pages: 91
    Keywords: tyrosyl-tRNA synthetase, genomic library, gene cloning, antibodies


  23. Type of paper: Mentorship

    Title: The activity and specificity of tyrosyl-tRNA synthetase from yeast Saccharomyces cerevisiae
    Faculty: Prirodoslovno-matematički Zagreb
    Date of defense: 02/27/91
    Number of pages: 96
    Author: Rubelj dr. Ivica
    Degree level: Ph.D.


  24. Type of paper: Mentorship

    Title: The cloning of the gene for tyrosyl-tRNA synthetase from yeast Saccharomyces cerevisiae
    Faculty: Prirodoslovno-matematički Zagreb
    Date of defense: 09/24/93
    Number of pages: 83
    Author: Sever mr. Sanja
    Degree level: M.A.


  25. Type of paper: Mentorship

    Title: Specific spin labeling of DNA
    Faculty: Prirodoslovno-matematički Zagreb
    Date of defense: 07/03/91
    Number of pages: 72
    Author: Šušić mr. Slavoljub
    Degree level: M.A.


  26. Type of paper: Mentorship

    Title: The screening of Saccharomyces cerevisiae genomic DNA library with antibodies against tyrosyl-tRNA synthetase
    Faculty: Prirodoslovno-matematički Zagreb
    Date of defense: 07/05/92
    Number of pages: 91
    Author: Pešić mr. Nenad
    Degree level: M.A.


  27. Type of paper: Invited lecture

    Title: Origins and perspectives of molecular biology in Croatia
    Institution: Matica Hrvatska
    Year: 1994


  28. Type of paper: Invited lecture

    Title: Molecular interpretation of life
    Institution: Matica Hrvatska
    Year: 1994


  29. Type of paper: Invited lecture

    Title: Biology, chemistry or philosophy?
    Institution: Academicus
    Year: 1995



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