5BJW

X-ray structure of the PglF 4,6-dehydratase from campylobacter jejuni, T595S variant, in complex with UDP

Summary for 5BJW

• Entry DOI: 10.2210/pdb5bjw/pdb
• Related: 5bju 5bjv
• Descriptor: WlaL protein, URIDINE-5'-DIPHOSPHATE, NICOTINAMIDE-ADENINE-DINUCLEOTIDE, ... (6 entities in total)
• Functional Keywords: short chain dehydrogenase, 4, 6-dehydratase, deoxysugar, membrane protein
• Biological source: Campylobacter jejuni
• Total number of polymer chains: 2
• Total formula weight: 84146.20

Authors

Riegert, A.S.,Thoden, J.B.,Holden, H.M. (deposition date: 2017-09-12, release date: 2017-11-08, Last modification date: 2023-09-27)

Primary citation

Riegert, A.S.,Thoden, J.B.,Schoenhofen, I.C.,Watson, D.C.,Young, N.M.,Tipton, P.A.,Holden, H.M.
Structural and Biochemical Investigation of PglF from Campylobacter jejuni Reveals a New Mechanism for a Member of the Short Chain Dehydrogenase/Reductase Superfamily.
Biochemistry, 56:6030-6040, 2017

PubMed Abstract: Within recent years it has become apparent that protein glycosylation is not limited to eukaryotes. Indeed, in Campylobacter jejuni, a Gram-negative bacterium, more than 60 of its proteins are known to be glycosylated. One of the sugars found in such glycosylated proteins is 2,4-diacetamido-2,4,6-trideoxy-α-d-glucopyranose, hereafter referred to as QuiNAc4NAc. The pathway for its biosynthesis, initiating with UDP-GlcNAc, requires three enzymes referred to as PglF, PglE, and PlgD. The focus of this investigation is on PglF, an NAD-dependent sugar 4,6-dehydratase known to belong to the short chain dehydrogenase/reductase (SDR) superfamily. Specifically, PglF catalyzes the first step in the pathway, namely, the dehydration of UDP-GlcNAc to UDP-2-acetamido-2,6-dideoxy-α-d-xylo-hexos-4-ulose. Most members of the SDR superfamily contain a characteristic signature sequence of YXXXK where the conserved tyrosine functions as a catalytic acid or a base. Strikingly, in PglF, this residue is a methionine. Here we describe a detailed structural and functional investigation of PglF from C. jejuni. For this investigation five X-ray structures were determined to resolutions of 2.0 Å or better. In addition, kinetic analyses of the wild-type and site-directed variants were performed. On the basis of the data reported herein, a new catalytic mechanism for a SDR superfamily member is proposed that does not require the typically conserved tyrosine residue.

PubMed: 29053280
DOI: 10.1021/acs.biochem.7b00910

Experimental method

X-RAY DIFFRACTION (1.6 Å)