2B4Q

Pseudomonas aeruginosa RhlG/NADP active-site complex

2B4Q の概要

• エントリーDOI: 10.2210/pdb2b4q/pdb
• 分子名称: Rhamnolipids biosynthesis 3-oxoacyl-[acyl-carrier-protein] reductase, NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE (3 entities in total)
• 機能のキーワード: pseudomonas aeruginosa, rhlg-nadp complex, oxidoreductase
• 由来する生物種: Pseudomonas aeruginosa
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 58797.47

構造登録者

Miller, D.J.,White, S.W. (登録日: 2005-09-26, 公開日: 2006-05-02, 最終更新日: 2024-02-14)

主引用文献

Miller, D.J.,Zhang, Y.-M.,Rock, C.O.,White, S.W.
Structure of RhlG, an Essential beta-Ketoacyl Reductase in the Rhamnolipid Biosynthetic Pathway of Pseudomonas aeruginosa.
J.Biol.Chem., 281:18025-18032, 2006

PubMed Abstract: Rhamnolipids are extracellular biosurfactants and virulence factors secreted by the opportunistic human pathogen Pseudomonas aeruginosa that are required for swarming motility. The rhlG gene is essential for rhamnolipid formation, and the RhlG enzyme is thought to divert fatty acid synthesis intermediates into the rhamnolipid biosynthetic pathway based on its similarity to FabG, the beta-ketoacyl-acyl carrier protein (ACP) reductase of type II fatty acid synthesis. Crystallographic analysis reveals that the overall structures of the RhlG.NADP+ and FabG.NADP+ complexes are indeed similar, but there are key differences related to function. RhlG does not undergo the conformational changes upon NADP(H) binding at the active site that in FabG are the structural basis of negative allostery. Also, the acyl chain-binding pocket of RhlG is narrow and rigid compared with the larger, flexible substrate-binding subdomain in FabG. Finally, RhlG lacks a positively charged/hydrophobic surface feature adjacent to the active site that is found on enzymes like FabG that recognize the ACP of fatty acid synthesis. RhlG catalyzed the NADPH-dependent reduction of beta-ketodecanoyl-ACP to beta-d-hydroxydecanoyl-ACP. However, the enzyme was 2000-fold less active than FabG in carrying out the same reaction. These structural and biochemical studies establish RhlG as a NADPH-dependent beta-ketoacyl reductase of the SDR protein superfamily and further suggest that the ACP of fatty acid synthesis does not carry the substrates for RhlG.

PubMed: 16624803
DOI: 10.1074/jbc.M601687200

実験手法

X-RAY DIFFRACTION (2.3 Å)