PDBsum entry 4xpl

Transferase

PDB id: 4xpl

Contents

Protein chain

141 a.a.

Ligands

ACO

Waters ×77

References listed in PDB file

Key reference

• Title: Structural analysis of pseh, The campylobacter jejuni n-Acetyltransferase involved in bacterial o-Linked glycosylation.
• Authors: W.S.Song, M.S.Nam, B.Namgung, S.I.Yoon.
• Ref.: Biochem Biophys Res Commun, 2015, 458, 843-848. [DOI no: 10.1016/j.bbrc.2015.02.041]
• PubMed id: 25698400

Abstract

Campylobacter jejuni is a bacterium that uses flagella for motility and causes worldwide acute gastroenteritis in humans. The C. jejuni N-acetyltransferase PseH (cjPseH) is responsible for the third step in flagellin O-linked glycosylation and plays a key role in flagellar formation and motility. cjPseH transfers an acetyl group from an acetyl donor, acetyl coenzyme A (AcCoA), to the amino group of UDP-4-amino-4,6-dideoxy-N-acetyl-β-l-altrosamine to produce UDP-2,4-diacetamido-2,4,6-trideoxy-β-l-altropyranose. To elucidate the catalytic mechanism of cjPseH, crystal structures of cjPseH alone and in complex with AcCoA were determined at 1.95 Å resolution. cjPseH folds into a single-domain structure of a central β-sheet decorated by four α-helices with two continuously connected grooves. A deep groove (groove-A) accommodates the AcCoA molecule. Interestingly, the acetyl end of AcCoA points toward an open space in a neighboring shallow groove (groove-S), which is occupied by extra electron density that potentially serves as a pseudosubstrate, suggesting that the groove-S may provide a substrate-binding site. Structure-based comparative analysis suggests that cjPseH utilizes a unique catalytic mechanism of acetylation that has not been observed in other glycosylation-associated acetyltransferases. Thus, our studies on cjPseH will provide valuable information for the design of new antibiotics to treat C. jejuni-induced gastroenteritis.