2XFS

Structural and mechanistic studies on a cephalosporin esterase from the clavulanic acid biosynthesis pathway

2XFS の概要

• エントリーDOI: 10.2210/pdb2xfs/pdb
• 関連するPDBエントリー: 2XEP 2XF3 2XFT 2XGN 2XH9
• 分子名称: ORF12, (2R,3Z,5R)-3-(2-HYDROXYETHYLIDENE)-7-OXO-4-OXA-1-AZABICYCLO[3.2.0]HEPTANE-2-CARBOXYLIC ACID (3 entities in total)
• 機能のキーワード: hydrolase
• 由来する生物種: STREPTOMYCES CLAVULIGERUS
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 100567.83

構造登録者

Iqbal, A.,Valegard, K.,Kershaw, N.J.,Ivison, D.,Genereux, C.,Dubus, A.,Andersson, I.,Schofield, C.J. (登録日: 2010-05-26, 公開日: 2011-06-29, 最終更新日: 2023-12-20)

主引用文献

Valegard, K.,Iqbal, A.,Kershaw, N.J.,Ivison, D.,Genereux, C.,Dubus, A.,Blikstad, C.,Demetriades, M.,Hopkinson, R.J.,Lloyd, A.J.,Roper, D.I.,Schofield, C.J.,Andersson, I.,McDonough, M.A.
Structural and mechanistic studies of the orf12 gene product from the clavulanic acid biosynthesis pathway.
Acta Crystallogr. D Biol. Crystallogr., 69:1567-1579, 2013

PubMed Abstract: Structural and biochemical studies of the orf12 gene product (ORF12) from the clavulanic acid (CA) biosynthesis gene cluster are described. Sequence and crystallographic analyses reveal two domains: a C-terminal penicillin-binding protein (PBP)/β-lactamase-type fold with highest structural similarity to the class A β-lactamases fused to an N-terminal domain with a fold similar to steroid isomerases and polyketide cyclases. The C-terminal domain of ORF12 did not show β-lactamase or PBP activity for the substrates tested, but did show low-level esterase activity towards 3'-O-acetyl cephalosporins and a thioester substrate. Mutagenesis studies imply that Ser173, which is present in a conserved SXXK motif, acts as a nucleophile in catalysis, consistent with studies of related esterases, β-lactamases and D-Ala carboxypeptidases. Structures of wild-type ORF12 and of catalytic residue variants were obtained in complex with and in the absence of clavulanic acid. The role of ORF12 in clavulanic acid biosynthesis is unknown, but it may be involved in the epimerization of (3S,5S)-clavaminic acid to (3R,5R)-clavulanic acid.

PubMed: 23897479
DOI: 10.1107/S0907444913011013

実験手法

X-RAY DIFFRACTION (1.8 Å)