A structural variation for MurB: X-ray crystal structure of Staphylococcusaureus UDP-N-acetylenolpyruvylglucosamine reductase (MurB)

The X-ray crystal structure of the substrate free form of Staphylococcus au reus UDP-N-acetylenolpyruvylglucosamine reductase (MurB) has been solved to 2.3 Angstrom resolution with an R-factor of 20.3% and a free R-factor of 2 2.3%. While the overall fold of the S. aureus enzyme is similar to that of the homologous Escherichia coli MurB X-ray crystal structure, notable disti nctions between the S. aureus and E. coli MurB protein structures occur in residues involved in substrate binding. Analysis of available MurB sequence s from other bacteria suggest that the S. aureus MurB structure is represen tative of a distinct structural class of UDP-N-acetylenolpyruvylglucosamine reductases including Bacillus subtilis and Helicobacter pylori that are ch aracterized by a modified mechanism for substrate binding.