1h79: Difference between revisions
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[[Image:1h79.gif|left|200px]]<br /><applet load="1h79" size=" | [[Image:1h79.gif|left|200px]]<br /><applet load="1h79" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1h79, resolution 2.9Å" /> | caption="1h79, resolution 2.9Å" /> | ||
'''STRUCTURAL BASIS FOR ALLOSTERIC SUBSTRATE SPECIFICITY REGULATION IN CLASS III RIBONUCLEOTIDE REDUCTASES: NRDD IN COMPLEX WITH DTTP'''<br /> | '''STRUCTURAL BASIS FOR ALLOSTERIC SUBSTRATE SPECIFICITY REGULATION IN CLASS III RIBONUCLEOTIDE REDUCTASES: NRDD IN COMPLEX WITH DTTP'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
1H79 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t2 Enterobacteria phage t2] with MG, FE2 and TTP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-triphosphate_reductase Ribonucleoside-triphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.2 1.17.4.2] Known structural/functional Site: <scene name='pdbsite=AC1:Ttp Binding Site For Chain A'>AC1</scene>. Full crystallographic information is available from [http:// | 1H79 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t2 Enterobacteria phage t2] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=FE2:'>FE2</scene> and <scene name='pdbligand=TTP:'>TTP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-triphosphate_reductase Ribonucleoside-triphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.2 1.17.4.2] Known structural/functional Site: <scene name='pdbsite=AC1:Ttp+Binding+Site+For+Chain+A'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1H79 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: substrate specificity]] | [[Category: substrate specificity]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:47:17 2008'' | ||
Revision as of 10:47, 3 February 2008
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STRUCTURAL BASIS FOR ALLOSTERIC SUBSTRATE SPECIFICITY REGULATION IN CLASS III RIBONUCLEOTIDE REDUCTASES: NRDD IN COMPLEX WITH DTTP
OverviewOverview
BACKGROUND: The specificity of ribonucleotide reductases (RNRs) toward, their four substrates is governed by the binding of deoxyribonucleoside, triphosphates (dNTPs) to the allosteric specificity site. Similar patterns, in the kinetics of allosteric regulation have been a strong argument for a, common evolutionary origin of the three otherwise widely divergent RNR, classes. Recent structural information settled the case for divergent, evolution; however, the structural basis for transmission of the, allosteric signal is currently poorly understood. A comparative study of, the conformational effects of the binding of different effectors has not, yet been possible; in addition, only one RNR class has been studied., RESULTS: Our presentation of the structures of a class III anaerobic RNR, in complex with four dNTPs allows a full comparison of the protein, conformations. Discrimination among the effectors is achieved by two side, chains, Gln-114 and Glu-181, from separate monomers. Large conformational, changes in the active site (loop 2), in particular Phe-194, are induced by, effector binding. The conformational differences observed in the protein, when the purine effectors are compared with the pyrimidine effectors are, large, while the differences observed within the purine group itself are, more subtle. CONCLUSIONS: The subtle differences in base size and hydrogen, bonding pattern at the effector site are communicated to major, conformational changes in the active site. We propose that the altered, overlap of Phe-194 with the substrate base governs hydrogen bonding, patterns with main and side chain hydrogen bonding groups in the active, site. The relevance for evolution is discussed.
About this StructureAbout this Structure
1H79 is a Single protein structure of sequence from Enterobacteria phage t2 with , and as ligands. Active as Ribonucleoside-triphosphate reductase, with EC number 1.17.4.2 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
Structural basis for allosteric substrate specificity regulation in anaerobic ribonucleotide reductases., Larsson KM, Andersson J, Sjoberg BM, Nordlund P, Logan DT, Structure. 2001 Aug;9(8):739-50. PMID:11587648
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