کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1391482 | 983286 | 2007 | 11 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A Tylosin Ketoreductase Reveals How Chirality Is Determined in Polyketides A Tylosin Ketoreductase Reveals How Chirality Is Determined in Polyketides](/preview/png/1391482.png)
SummaryBecause it controls the majority of polyketide stereocenters, the ketoreductase (KR) is a central target in engineering polyketide synthases (PKSs). To elucidate the mechanisms of stereocontrol, the structure of KR from the first module of the tylosin PKS was determined. A comparison with a recently solved erythromycin KR that operates on the same substrate explains why their products have opposite α-substituent chiralities. The structure reveals how polyketides are guided into the active site by key residues in different KR types. There are four types of reductase-competent KRs, each capable of fixing a unique combination of α-substituent and β-hydroxyl group chiralities, as well as two types of reductase-incompetent KRs that control α-substituent chirality alone. A protocol to assign how a module will enforce substituent chirality based on its sequence is presented.
Journal: - Volume 14, Issue 8, 24 August 2007, Pages 898–908