3qp9: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
==The Structure of a C2-type Ketoreductase from a Modular Polyketide Synthase== | |||
<StructureSection load='3qp9' size='340' side='right' caption='[[3qp9]], [[Resolution|resolution]] 1.88Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3qp9]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Streptomyces_venezuelae Streptomyces venezuelae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3QP9 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3QP9 FirstGlance]. <br> | |||
</td></tr><tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">pikAII ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=54571 Streptomyces venezuelae])</td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/3-oxoacyl-[acyl-carrier-protein]_reductase 3-oxoacyl-[acyl-carrier-protein] reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.100 1.1.1.100] </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=3qp9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3qp9 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3qp9 RCSB], [http://www.ebi.ac.uk/pdbsum/3qp9 PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The process by which alpha-stereocenters of polyketide intermediates are set by modular polyketide synthases (PKSs) when condensation is not immediately followed by reduction is mysterious. However, the reductase-incompetent ketoreductase (KR) from the third module of 6-deoxyerythronolide B synthase has been proposed to operate as a racemase, aiding in the epimerization process that reverses the orientation of the alpha-methyl group of the polyketide intermediate generated by the ketosynthase to the configuration observed in the 6-deoxyerythronolide B final product. To learn more about the epimerization process, the structure of the C2-type KR from the third module of the pikromycin synthase, analogous to the KR from the third module of 6-deoxyerythronolide B synthase, was determined to 1.88 A resolution. This first structural analysis of this KR-type reveals differences from reductase-competent KRs such as that the site NADPH binds to reductase-competent KRs is occluded by side chains and the putative catalytic tyrosine possesses more degrees of freedom. The active-site geometry may enable C2-type KRs to align the thioester and beta-keto groups of a polyketide intermediate to reduce the pK(a) of the alpha-proton and accelerate its abstraction. Results from in vivo assays of engineered PKSs support that C2-type KRs cooperate with epimer-specific ketosynthases to set the configurations of substituent-bearing alpha-carbons. | |||
Structural and functional analysis of c2-type ketoreductases from modular polyketide synthases.,Zheng J, Keatinge-Clay AT J Mol Biol. 2011 Jul 1;410(1):105-17. Epub 2011 May 5. PMID:21570406<ref>PMID:21570406</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Streptomyces venezuelae]] | [[Category: Streptomyces venezuelae]] | ||
[[Category: Keatinge-Clay, A T | [[Category: Keatinge-Clay, A T]] | ||
[[Category: Zheng, J | [[Category: Zheng, J]] | ||
[[Category: Epimerization]] | [[Category: Epimerization]] | ||
[[Category: Ketoreductase]] | [[Category: Ketoreductase]] | ||
[[Category: Oxidoreductase]] | [[Category: Oxidoreductase]] | ||
[[Category: Rossmann fold]] | [[Category: Rossmann fold]] | ||
