type	Journal Article
authors	Dow GT, Gilbert M, Thoden JB, Holden HM
title	Structural investigation on WlaRG from Campylobacter jejuni: A sugar aminotransferase
journal	Protein Sci
Activity	2.6.1.90
Family	2.6.1.90.a
sel	selected
ui	28028852
year	(2017)
volume	26
number	3
pages	586-599
keywords	Campylobacter jejuni; WbpE; WlaRG; aminotransferase; dTDP-3-amino-3,6-dideoxy-d-galactose; dTDP-3-amino-3,6-dideoxy-d-glucose; lipooligosaccharide; pyridoxal 5′-phosphate
abstract	Campylobacter jejuni is a Gram-negative bacterium that represents a leading cause of human gastroenteritis worldwide. Of particular concern is the link between C. jejuni infections and the subsequent development of Guillain-Barré syndrome, an acquired autoimmune disorder leading to paralysis. All Gram-negative bacteria contain complex glycoconjugates anchored to their outer membranes, but in most strains of C. jejuni, this lipoglycan lacks the O-antigen repeating units. Recent mass spectrometry analyses indicate that the C. jejuni 81116 (Penner serotype HS:6) lipoglycan contains two dideoxyhexosamine residues, and enzymological assay data show that this bacterial strain can synthesize both dTDP-3-acetamido-3,6-dideoxy-d-glucose and dTDP-3-acetamido-3,6-dideoxy-d-galactose. The focus of this investigation is on WlaRG from C. jejuni, which plays a key role in the production of these unusual sugars by functioning as a pyridoxal 5'-phosphate dependent aminotransferase. Here, we describe the first three-dimensional structures of the enzyme in various complexes determined to resolutions of 1.7 Å or higher. Of particular significance are the external aldimine structures of WlaRG solved in the presence of either dTDP-3-amino-3,6-dideoxy-d-galactose or dTDP-3-amino-3,6-dideoxy-d-glucose. These models highlight the manner in which WlaRG can accommodate sugars with differing stereochemistries about their C-4' carbon positions. In addition, we present a corrected structure of WbpE, a related sugar aminotransferase from Pseudomonas aeruginosa, solved to 1.3 Å resolution.
last changed	2019/05/31 10:58