Inhibition of beta-lactamase by clavulanate. Trapped intermediates in cryocrystallographic studies.Chen, C.C., Herzberg, O.
(1992) J Mol Biol 224: 1103-1113
- PubMed: 1569569
- DOI: 10.1016/0022-2836(92)90472-v
- Primary Citation of Related Structures:
- PubMed Abstract:
- Structure of a Phosphonate-Inhibited Beta-Lactamase: An Analog of the Tetrahedral Transition State(Slash)Intermediate of Beta-Lactam Hydrolysis
Chen, C.C.H., Rahil, J., Pratt, R.F., Herzberg, O.
() To be published --: --
- Refined Crystal Structure of Beta-Lactamase from Staphylococcus Aureus Pc1 at 2.0 Angstroms Resolution
(1991) J Mol Biol 217: 701
- Structural Basis for the Inactivation of the P54 Mutant of Beta-Lactamase from Staphylococcus Aureus Pc1
Herzberg, O., Kapadia, G., Blanco, B., Smith, T.S., Coulson, A.
(1991) Biochemistry 30: 9503
- Penicillin-Binding and Degrading Enzymes
Herzberg, O., Moult, J.
(1991) Curr Opin Struct Biol 1: 946
- Bacterial Resistance to Beta-Lactam Antibiotics. Crystal Structure of Beta-Lactamase from Staphylococcus Aureus Pc1 at 2.5 Angstroms Resolution
Herzberg, O., Moult, J.
(1987) Science 236: 694
- The Crystal Structure of Beta-Lactamase from Staphylococcus Aureus at 0.5Nm Resolution
Moult, J., Sawyer, L., Herzberg, O., Jones, C.L., Coulson, A.F.W., Green, D.W., Harding, M.M., Ambler, R.P.
(1985) J Biochem 225: 167
Crystallographic studies of the complex between beta-lactamase and clavulanate reveal a structure of two acyl-enzymes with covalent bonds at the active site Ser70, representing two different stages of inhibitor degradation alternately occupying the active site ...
Crystallographic studies of the complex between beta-lactamase and clavulanate reveal a structure of two acyl-enzymes with covalent bonds at the active site Ser70, representing two different stages of inhibitor degradation alternately occupying the active site. Models that are consistent with biochemical data are derived from the electron density map and refined at 2.2 A resolution: cis enamine, in which the carboxylate group of the clavulanate molecule makes a salt bridge with Lys234 of beta-lactamase; decarboxylated trans enamine, which is oriented away from Lys234. For both acyl-enzymes, the carbonyl oxygen atom of the ester group occupies the oxyanion hole in a manner similar to that found in inhibitor binding to serine proteases. Whereas the oxygen atom in the trans product is optimally positioned in the oxyanion hole, that of the cis product clashes with the main-chain nitrogen atom of Ser70 and the beta-carbon atom of the adjacent Ala69. In contrast to cis to trans isomerization in solution that relieves the steric strain inherent in a cis double bond, at the enzyme-inhibitor interface two additional factors play an important role. The salt bridge enhances the stability of the cis product, while the steric strain introduced by the short contacts with the protein reduces its stability.
Center for Advanced Research in Biotechnology, Maryland Biotechnology Institute, University of Maryland, Rockville 20850.