X-ray crystal structures of the S229A mutant and wild-type MurB in the presence of the substrate enolpyruvyl-UDP-N-acetylglucosamine at 1.8-A resolution.Benson, T.E., Walsh, C.T., Hogle, J.M.
(1997) Biochemistry 36: 806-811
- PubMed: 9020778
- DOI: 10.1021/bi962221g
- Primary Citation of Related Structures:
- PubMed Abstract:
- An Enzyme-Substrate Complex Involved in Bacterial Cell Wall Biosynthesis
Benson, T.E.,Filman, D.J.,Walsh, C.T.,Hogle, J.M.
(1995) Nat.Struct.Mol.Biol. 2: 644
- Crystallization and Preliminary X-Ray Crystallographic Studies of Udp-N-Acetyl Enolpyruvylglucosamine Reductase
Benson, T.E.,Walsh, C.T.,Hogle, J.M.
(1994) Int.Immunol. 3: 1125
- Overexpression, Purification, and Mechanistic Study of Udp-N-Acetylenolpyruvylglucosamine Reductase
Benson, T.E.,Marquardt, J.L.,Marquardt, A.C.,Etzkorn, F.A.,Walsh, C.T.
(1993) Biochemistry 32: 2024
- Kinetic Characterization of Wild-Type and S229A Mutant Murb: Evidence for the Role of Ser 229 as a General Acid
Benson, T.E.,Walsh, C.T.,Massey, V.
(1997) Biochemistry 36: 796
MurB catalyzes the second committed step in the synthesis of peptidoglycan, a key component of the bacterial cell wall. The crystal structures of both a S229A mutant and wild-type MurB in the presence of the substrate enolpyruvyl-UDP-N-acetylglucosam ...
MurB catalyzes the second committed step in the synthesis of peptidoglycan, a key component of the bacterial cell wall. The crystal structures of both a S229A mutant and wild-type MurB in the presence of the substrate enolpyruvyl-UDP-N-acetylglucosamine were solved and refined at 1.8 A resolution. The single point mutation of residue 229 from serine to alanine eliminated a hydroxyl group which has previously been proposed to play a critical role as a proton donor during the second half-reaction of MurB, namely, reoxidation of FADH2 and reduction of the enolpyruvyl substrate. The mutation also resulted in the loss of the water molecule-hydrogen bonded to the serine hydroxyl in the wild-type structure changing the hydrogen-bonding network with in the active site. Comparison of the wild-type and S229A mutant structures confirms that the dramatic kinetic defect of an approximately 10(7)-fold decrease observed for the Ser 229 Ala mutant in the second half-reaction [Benson, T.E., Walsh, C.T., & Massey, V. (1997) Biochemistry 36, 796-805] is a direct result of the loss of the serine hydroxyl moiety rather than other nonspecific active-site changes or general structural defects.
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.