1uxy
From Proteopedia
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MURB MUTANT WITH SER 229 REPLACED BY ALA, COMPLEX WITH ENOLPYRUVYL-UDP-N-ACETYLGLUCOSAMINE
Overview
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.
About this Structure
1UXY is a Single protein structure of sequence from Escherichia coli with FAD and EPU as ligands. Active as UDP-N-acetylmuramate dehydrogenase, with EC number 1.1.1.158 Full crystallographic information is available from OCA.
Reference
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 TE, Walsh CT, Hogle JM, Biochemistry. 1997 Jan 28;36(4):806-11. PMID:9020778
Page seeded by OCA on Wed Nov 21 04:21:25 2007
