24758-79-0Relevant academic research and scientific papers
A fluorescent analogue of UDP-N-acetylglucosamine: Application for FRET assay of peptidoglycan translocase II (MurG)
Li, Jian-Jun,Bugg, Timothy D. H.
, p. 182 - 183 (2004)
A direct continuous fluorescence assay for translocase II MurG based on fluorescence resonance energy transfer (FRET) has been developed using a 6-substituted fluorescent analogue of UDP-N-acetylglucosamine.
Molecular structure of wlbb, a bacterial N -acetyltransferase involved in the biosynthesis of 2,3-diacetamido-2,3-dideoxy-D -mannuronic acid
Thoden, James B.,Holden, Hazel M.
experimental part, p. 4644 - 4653 (2011/03/21)
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 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 LβH superfamily of N-acyltransferases. Each subunit contains 27 β-strands, 23 of which form the canonical left-handed β-helix. There are only two hydrogen bonds that occur between the protein and the GlcNAc3NA moiety, one between O?1 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.
Structural and functional studies of WlbA: A dehydrogenase involved in the biosynthesis of 2,3-diacetamido-2,3-dideoxy- D -mannuronic acid
Thoden, James B.,Holden, Hazel M.
experimental part, p. 7939 - 7948 (2011/11/06)
2,3-Diacetamido-2,3-dideoxy-d-mannuronic acid (ManNAc3NAcA) is an unusual dideoxy sugar first identified nearly 30 years ago in the lipopolysaccharide of Pseudomonas aeruginosa O:3a,d. It has since been observed in other organisms, including Bordetella pertussis, the causative agent of whooping cough. Five enzymes are required for the biosynthesis of UDP-ManNAc3NAcA starting from UDP-N-acetyl-d-glucosamine. Here we describe a structural study of WlbA, the NAD-dependent dehydrogenase that catalyzes the second step in the pathway, namely, the oxidation of the C-3′ hydroxyl group on the UDP-linked sugar to a keto moiety and the reduction of NAD+ to NADH. This enzyme has been shown to use α-ketoglutarate as an oxidant to regenerate the oxidized dinucleotide. For this investigation, three different crystal structures were determined: the enzyme with bound NAD(H), the enzyme in a complex with NAD(H) and α-ketoglutarate, and the enzyme in a complex with NAD(H) and its substrate (UDP-N-acetyl-d-glucosaminuronic acid). The tetrameric enzyme assumes an unusual quaternary structure with the dinucleotides positioned quite closely to one another. Both α-ketoglutarate and the UDP-linked sugar bind in the WlbA active site with their carbon atoms (C-2 and C-3′, respectively) abutting the re face of the cofactor. They are positioned ～3 A from the nicotinamide C-4. The UDP-linked sugar substrate adopts a highly unusual curved conformation when bound in the WlbA active site cleft. Lys 101 and His 185 most likely play key roles in catalysis.
