PDBsum entry 4lxq

Transferase

PDB id: 4lxq

Contents

Protein chains

273 a.a.

Ligands

FON ×2

TYD ×2

MPO ×4

EDO ×9

EDO-EDO

Metals

_CL ×7

Waters ×1024

PDB id:

4lxq

Name:

Transferase

Title:

Crystal structure wlard, a sugar 3n-formyl transferase in the presence of dtdp and 5-n-formyl-thf

Structure:

Wlard, a sugar 3n-formyl transferase. Chain: a, b. Engineered: yes

Source:

Campylobacter jejuni subsp. Jejuni. Organism_taxid: 407148. Strain: 81116. Gene: c8j_1081. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.40Å R-factor: 0.159 R-free: 0.178

Authors:

J.B.Thoden,M.-F.Goneau,M.Gilbert,H.M.Holden

Key ref:

J.B.Thoden et al. (2013). Structure of a sugar N-formyltransferase from Campylobacter jejuni. Biochemistry, 52, 6114-6126. PubMed id: 23898784 DOI: 10.1021/bi4009006

Date:

30-Jul-13 Release date: 14-Aug-13

Protein chains

A8FMJ3  (A8FMJ3_CAMJ8) -

DOI no: 10.1021/bi4009006

Biochemistry 52:6114-6126 (2013)

PubMed id: 23898784

Structure of a sugar N-formyltransferase from Campylobacter jejuni.

J.B.Thoden, M.F.Goneau, M.Gilbert, H.M.Holden.

ABSTRACT

The O-antigens, which are components of the outer membranes of Gram-negative bacteria, are responsible for the wide species variations seen in nature and are thought to play a role in bacterial virulence. They often contain unusual dideoxysugars such as 3,6-dideoxy-3-formamido-d-glucose (Qui3NFo). Here, we describe a structural and functional investigation of the protein C8J_1081 from Campylobacter jejuni 81116, which is involved in the biosynthesis of Qui3NFo. Specifically, the enzyme, hereafter referred to as WlaRD, catalyzes the N-formylation of dTDP-3,6-dideoxy-3-amino-d-glucose (dTDP-Qui3N) using N(10)-formyltetrahydrofolate as the carbon source. For this investigation, seven X-ray structures of WlaRD, in complexes with various dTDP-linked sugars and cofactors, were determined to resolutions of 1.9 Å or better. One of the models, with bound N(10)-formyltetrahydrofolate and dTDP, represents the first glimpse of an N-formyltransferase with its natural cofactor. Another model contains the reaction products, tetrahydrofolate and dTDP-Qui3NFo. In combination, the structures provide snapshots of the WlaRD active site before and after catalysis. On the basis of these structures, three amino acid residues were targeted for study: Asn 94, His 96, and Asp 132. Mutations of any of these residues resulted in a complete loss of enzymatic activity. Given the position of His 96 in the active site, it can be postulated that it functions as the active site base to remove a proton from the sugar amino group as it attacks the carbonyl carbon of the N-10 formyl group of the cofactor. Enzyme assays demonstrate that WlaRD is also capable of utilizing dTDP-3,6-dideoxy-3-amino-d-galactose (dTDP-Fuc3N) as a substrate, albeit at a much reduced catalytic efficiency.