1c8w: Difference between revisions
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1c8w]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C8W OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1C8W FirstGlance]. <br> | <table><tr><td colspan='2'>[[1c8w]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C8W OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1C8W FirstGlance]. <br> | ||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>< | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene></td></tr> | ||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1c8w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1c8w OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1c8w RCSB], [http://www.ebi.ac.uk/pdbsum/1c8w PDBsum]</span></td></tr> | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1c8w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1c8w OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1c8w RCSB], [http://www.ebi.ac.uk/pdbsum/1c8w PDBsum]</span></td></tr> | ||
<table> | </table> | ||
== Evolutionary Conservation == | == Evolutionary Conservation == | ||
[[Image:Consurf_key_small.gif|200px|right]] | [[Image:Consurf_key_small.gif|200px|right]] | ||
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==See Also== | ==See Also== | ||
*[[Ribonuclease|Ribonuclease]] | *[[Ribonuclease|Ribonuclease]] | ||
*[[Temp|Temp]] | |||
*[[User:Jaime.Prilusky/Test/tree|User:Jaime.Prilusky/Test/tree]] | |||
== References == | == References == | ||
<references/> | <references/> | ||
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</StructureSection> | </StructureSection> | ||
[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Kelemen, B R | [[Category: Kelemen, B R]] | ||
[[Category: Raines, R T | [[Category: Raines, R T]] | ||
[[Category: Schultz, L W | [[Category: Schultz, L W]] | ||
[[Category: Sweeney, R T | [[Category: Sweeney, R T]] | ||
[[Category: Anti-parallel beta sheet]] | [[Category: Anti-parallel beta sheet]] | ||
[[Category: Hydrolase]] | [[Category: Hydrolase]] | ||
[[Category: Rnase some]] | [[Category: Rnase some]] | ||
Revision as of 12:55, 22 December 2014
THR45GLY VARIANT OF RIBONUCLEASE ATHR45GLY VARIANT OF RIBONUCLEASE A
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedRibonuclease A (RNase A) catalyzes the cleavage of RNA after pyrimidine nucleotides. When bound in the active site, the base of a pyrimidine nucleotide forms hydrogen bonds with the side chain of Thr45. Here, the role of Thr45 was probed by using the wild-type enzyme, its T45G variant, X-ray diffraction analysis, and synthetic oligonucleotides as ligands and substrates. Catalytic specificity was determined with the fluorogenic substrate: 6-carboxyfluorescein approximately dArXdAdA approximately 6-carboxytetramethylrhodamine (6-FAM approximately dArXdAdA approximately 6-TAMRA), where X = C, U, A, or G. Wild-type RNase A cleaves 10(6)-fold faster when X = C than when X = A. Likewise, its affinity for the non-hydrolyzable oligonucleotide 6-FAM approximately d(CAA) is 50-fold greater than for 6-FAM approximately d(AAA). T45G RNase A cleaves 6-FAM approximately dArAdAdA approximately 6-TAMRA 10(2)-fold faster than does the wild-type enzyme. The structure of crystalline T45G RNase A, determined at 1.8-A resolution by X-ray diffraction analysis, does not reveal new potential interactions with a nucleobase. Indeed, the two enzymes have a similar affinity for 6-FAM approximately d(AAA). The importance of pentofuranosyl ring conformation to nucleotide specificity was probed with 6-FAM approximately d(AU(F)AA), where U(F) is 2'-deoxy-2'-fluorouridine. The conformation of the pentofuranosyl ring in dU(F) is known to be more similar to that in rU than dU. The affinity of wild-type RNase A for 6-FAM approximately d(AU(F)AA) is 50-fold lower than for 6-FAM approximately d(AUAA). This discrimination is lost in the T45G enzyme. Together, these data indicate that the side chain of Thr45 plays multiple roles-interacting favorably with pyrimidine nucleobases but unfavorably with purine nucleobases. Moreover, a ribose-like ring disfavors the interaction of Thr45 with a pyrimidine nucleobase, suggesting that Thr45 enhances catalysis by ground-state destabilization. Excavating an active site: the nucleobase specificity of ribonuclease A.,Kelemen BR, Schultz LW, Sweeney RY, Raines RT Biochemistry. 2000 Nov 28;39(47):14487-94. PMID:11087402[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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