3MQG

crystal structure of the 3-N-acetyl transferase WlbB from Bordetella petrii in complex with acetyl-CoA

Summary for 3MQG

• Entry DOI: 10.2210/pdb3mqg/pdb
• Related: 3MQH
• Descriptor: Lipopolysaccharides biosynthesis acetyltransferase, ACETYL COENZYME *A, URIDINE-5'-MONOPHOSPHATE, ... (9 entities in total)
• Functional Keywords: beta helix, acetyl transferase, biosynthesis, transferase
• Biological source: Bordetella petrii
• Total number of polymer chains: 6
• Total formula weight: 132914.91

Authors

Thoden, J.B.,Holden, H.M. (deposition date: 2010-04-28, release date: 2010-05-12, Last modification date: 2024-04-03)

Primary citation

Thoden, J.B.,Holden, H.M.
Molecular structure of WlbB, a bacterial N-acetyltransferase involved in the biosynthesis of 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid .
Biochemistry, 49:4644-4653, 2010

PubMed Abstract: The pathogenic bacteria Pseudomonas aeruginosa and Bordetella pertussis contain in their outer membranes the rare sugar 2,3-diacetamido-2,3-dideoxy-d-mannuronic acid. Five enzymes are required for the biosynthesis of this sugar starting from UDP-N-acetylglucosamine. One of these, referred to as WlbB, is an N-acetyltransferase that converts UDP-2-acetamido-3-amino-2,3-dideoxy-d-glucuronic acid (UDP-GlcNAc3NA) to UDP-2,3-diacetamido-2,3-dideoxy-d-glucuronic acid (UDP-GlcNAc3NAcA). Here we report the three-dimensional structure of WlbB from Bordetella petrii. For this analysis, two ternary structures were determined to 1.43 A resolution: one in which the protein was complexed with acetyl-CoA and UDP and the second in which the protein contained bound CoA and UDP-GlcNAc3NA. WlbB adopts a trimeric quaternary structure and belongs to the LbetaH superfamily of N-acyltransferases. Each subunit contains 27 beta-strands, 23 of which form the canonical left-handed beta-helix. There are only two hydrogen bonds that occur between the protein and the GlcNAc3NA moiety, one between O(delta1) of Asn 84 and the sugar C-3' amino group and the second between the backbone amide group of Arg 94 and the sugar C-5' carboxylate. The sugar C-3' amino group is ideally positioned in the active site to attack the si face of acetyl-CoA. Given that there are no protein side chains that can function as general bases within the GlcNAc3NA binding pocket, a reaction mechanism is proposed for WlbB whereby the sulfur of CoA ultimately functions as the proton acceptor required for catalysis.

PubMed: 20433200
DOI: 10.1021/bi1005738

Experimental method

X-RAY DIFFRACTION (1.43 Å)