PDBsum entry 1mbb

Oxidoreductase

PDB id: 1mbb

Contents

Protein chain

340 a.a. *

Ligands

EEB

FAD

Waters ×119

* Residue conservation analysis

PDB id:

1mbb

Name:

Oxidoreductase

Title:

Oxidoreductase

Structure:

Uridine diphospho-n-acetylenolpyruvylglucosamine reductase. Chain: a. Synonym: murb. Other_details: (e)-enolbutryrl-udp-n-acetylglucosamine, bound flavin- adenine dinucleotide, ph 8.0

Source:

Escherichia coli. Organism_taxid: 562. Strain: ab1157 (atcc)

Resolution:

2.30Å R-factor: 0.238 R-free: 0.324

Authors:

T.E.Benson,W.J.Lees,C.T.Walsh,J.M.Hogle

Key ref:

W.J.Lees et al. (1996). (E)-enolbutyryl-UDP-N-acetylglucosamine as a mechanistic probe of UDP-N-acetylenolpyruvylglucosamine reductase (MurB). Biochemistry, 35, 1342-1351. PubMed id: 8634262 DOI: 10.1021/bi952287w

Date:

07-Nov-95 Release date: 14-Oct-96

Protein chain

P08373  (MURB_ECOLI) -  UDP-N-acetylenolpyruvoylglucosamine reductase from Escherichia coli (strain K12)

Seq: 342 a.a.

Struc: 340 a.a.

Enzyme reactions

• Enzyme class: E.C.1.3.1.98 - UDP-N-acetylmuramate dehydrogenase.
• Reaction: UDP-N-acetyl-alpha-D-muramate + NADP⁺ = UDP-N-acetyl-3- O-(1-carboxyvinyl)-alpha-D-glucosamine + NADPH + H⁺
• Cofactor: FAD

FAD (Bound ligand (Het Group name = FAD) corresponds exactly)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1021/bi952287w

Biochemistry 35:1342-1351 (1996)

PubMed id: 8634262

(E)-enolbutyryl-UDP-N-acetylglucosamine as a mechanistic probe of UDP-N-acetylenolpyruvylglucosamine reductase (MurB).

W.J.Lees, T.E.Benson, J.M.Hogle, C.T.Walsh.

ABSTRACT

UDP-N-acetylenolpyruvylglucosamine reductase (MurB), a peptidoglycan biosynthetic enzyme from Escherichia coli, reduces both (E)- and (Z)-isomers of enolbutyryl-UDP-GlcNAc, C4 analogs of the physiological C3 enolpyruvyl substrate, to UDP-methyl-N-acetylmuramic acid in the presence of NADPH. The X-ray crystal structure of the (E)-enolbutyryl-UDP-GlcNAc-MurB complex is similar to that of the enolpyruvyl-UDP-GlcNAc-MurB complex. In both structures the groups thought to be involved in hydride transfer to C3 and protonation at C2 of the enol ether substrate are arranged anti relative to the enol double bond. The stereochemical outcome of reduction of (E)-enolbutyryl-UDP-GlcNAc by NADPD in D2O is thus predicted to yield a (2R,3R)-dideuterio product. This was validated by conversion of the 2,3-dideuterio-UDP-methyl-N-acetylmuramic acid product to 2,3-dideuterio-2-hydroxybutyrate, which was shown to be (2R) by enzymatic analysis and (3R) by NMR comparison to authentic (2R,3R)- and (2R,3S)-2,3-dideuterio-2-hydroxybutyrate. Remarkably, the (E)-enolbutyryl-UDP-GlcNAc was found to partition between reduction to UDP-methyl-N-acetylmuramic and isomerization to the (Z)-substrate isomer in the MurB active site, indicative of a C2 carbanion/enol species that is sufficiently long-lived to rotate around the C2-C3 single bond during catalysis.