PMID: 27171345

Authors:

Genthe NA, Thoden JB, Holden HM

Title:

Structure of the Escherichia coli ArnA N-Formyltransferase Domain in Complex with N -formyltetrahydrofolate and UDP-Ara4N.

Journal:

Protein Sci. 2016 May 12. doi: 10.1002/pro.2938.

Abstract:

ArnA from Escherichia coli is a key enzyme involved in the formation of 4-amino-4-deoxy-l-arabinose. The addition of this sugar to the lipid A moiety of the lipopolysaccharide of pathogenic Gram-negative bacteria allows these organisms to evade the cationic antimicrobial peptides of the host immune system. Indeed, it is thought that such modifications may be responsible for the repeated infections of cystic fibrosis patients with Pseudomonas aeruginosa. ArnA is a bifunctional enzyme with the N- and C-terminal domains catalyzing formylation and oxidative decarboxylation reactions, respectively. The catalytically competent cofactor for the formylation reaction is N10 -formyltetrahydrofolate. Here we describe the structure of the isolated N-terminal domain of ArnA in complex with its UDP-sugar substrate and N5 -formyltetrahydrofolate. The model presented herein may prove valuable in the development of new antimicrobial therapeutics. This article is protected by copyright. All rights reserved.