Crystal Structures of Enoyl-ACP Reductases I (FabI) and III (FabL) from B. subtilis

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• 作者：Kook-Han Kim¹ ; ² ; Byung Hak Ha¹ ; Su Jin Kim¹ ; Seung Kon Hong¹ ; Kwang Yeon Hwang² ; Eunice EunKyeong Kim¹ ; ^{eunice@kist.re.kr}
• 关键词：fatty acid biosynthesis ; enoyl-ACP reductase ; FabI ; FabL ; crystal structure
• 刊名：Journal of Molecular Biology
• 出版年：2011
• 出版时间：25 February 2011
• 年：2011
• 卷：406
• 期：3
• 页码：403-415
• 全文大小：2155 K

文摘

Enoyl-[acyl carrier protein] (ACP) reductase (ENR) is a key enzyme in type II fatty acid synthesis that catalyzes the last step in each elongation cycle. Therefore, it has been considered as a target for antibiotics. However, recent studies indicate that some pathogens have more than one ENR; in particular, Bacillus subtilis has two ENRs, FabI and FabL. The crystal structures of the ternary complexes of BsFaBI and BsFabL are found as a homotetramer showing the same overall structure despite a sequence identity of only 24 % . The positions of the catalytic dyad of Tyr-(Xaa)₆-Lys in FabL are almost identical to that of FabI, but a detailed structural analysis shows that FabL shares more structural similarities with FabG and other members of the SDR (short-chain alcohol dehydrogenase/reductase) family. The apo FabL structure shows significantly different conformations at the cofactor and the substrate-binding regions, and this resulted in a totally different tetrameric arrangement reflecting the flexibility of these regions in the absence of the cofactor and substrate/inhibitor.