2IU8

Chlamydia trachomatis LpxD with 25mM UDPGlcNAc (Complex I)

2IU8 の概要

• エントリーDOI: 10.2210/pdb2iu8/pdb
• 関連するPDBエントリー: 2IU9 2IUA
• 分子名称: UDP-3-O-[3-HYDROXYMYRISTOYL] GLUCOSAMINE N-ACYLTRANSFERASE, SULFATE ION, PALMITIC ACID, ... (7 entities in total)
• 機能のキーワード: transferase, udp-3- o-acyl-glucosamine n-acyltransferase, acyltransferase, lipid a biosynthesis, left-handed beta helix, complex with udpglcnac, enzyme, homotrimer, lipid synthesis
• 由来する生物種: CHLAMYDIA TRACHOMATIS
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 123981.20

構造登録者

Buetow, L.,Smith, T.K.,Dawson, A.,Fyffe, S.,Hunter, W.N. (登録日: 2006-05-30, 公開日: 2007-02-20, 最終更新日: 2024-05-08)

主引用文献

Buetow, L.,Smith, T.K.,Dawson, A.,Fyffe, S.,Hunter, W.N.
Structure and Reactivity of Lpxd, the N-Acyltransferase of Lipid a Biosynthesis
Proc.Natl.Acad.Sci.USA, 104:4321-, 2007

PubMed Abstract: The external layer of the Gram-negative bacterial outer membrane is primarily composed of a protective, selectively permeable LPS. The biosynthesis of LPS relies on UDP-3-O-acyl-glucosamine N-acyltransferase (LpxD), which transfers 3-hydroxy-arachidic acid from acyl carrier protein to the 2' amine of UDP-3-O-myristoyl glucosamine in Chlamydia trachomatis. Our crystallographic study reveals that LpxD is a homotrimer, each subunit of which is constructed from a novel combination of an N-terminal uridine-binding domain, a core lipid-binding domain, and a C-terminal helical extension. Highly conserved residues dominate nucleotide binding. Phe-43 and Tyr-49 form pi-stacking interactions with uracil, and Asn-46 and His-284 form hydrogen bonds with the phosphate groups. These interactions place the glucosamine moiety at the catalytic center formed by two adjacent subunits. Here His-247 and His-284 contribute to a mechanism involving nucleophilic attack by the amine of one substrate on the carbonyl carbon of an acyl carrier protein thioester conjugate. Serendipitously, our study reveals a fatty acid (FA) binding groove near the catalytic center. MS elucidated the presence of a FA mixture binding to LpxD, with palmitic acid the most prevalent. The placement of UDP-N-acetylglucosamine and the FA provides details of N-acyltransferase ligand interactions and allows for a description of structure and reactivity at an early stage of LPS assembly.

PubMed: 17360522
DOI: 10.1073/PNAS.0606356104

実験手法

X-RAY DIFFRACTION (2.2 Å)