Binding of cephalothin and cefotaxime to D-ala-D-ala-peptidase reveals a functional basis of a natural mutation in a low-affinity penicillin-binding protein and in extended-spectrum beta-lactamases.Kuzin, A.P., Liu, H., Kelly, J.A., Knox, J.R.
(1995) Biochemistry 34: 9532-9540
- PubMed: 7626623
- Primary Citation of Related Structures:  1CEG
- PubMed Abstract:
- Crystallographic Mapping of Beta-Lactams Bound to a D-Alanyl-D-Alanine Peptidase Target Enzyme
Kelly, J.A.,Knox, J.R.,Zhao, H.,Frere, J.M.,Ghaysen, J.M.
(1989) J.Mol.Biol. 209: 281
- 2.8-A Structure of Penicillin-Sensitive D-Alanyl Carboxypeptidase-Transpeptidase from Streptomyces R61 and Complexes with Beta-Lactams
Kelly, J.A.,Knox, J.R.,Moews, P.C.,Hite, G.J.,Bartolone, J.B.,Zhao, H.,Joris, B.,Frere, J.M.,Ghuysen, J.M.
(1985) J.Biol.Chem. 260: 6449
- The Refined Crystallographic Structure of a Dd-Peptidase Penicillin-Target Enzyme at 1.6 A Resolution
Kelly, J.A.,Kuzin, A.P.
(1995) J.Mol.Biol. 254: 223
- On the Origin of Bacterial Resistance to Penicillin: Comparison of a Beta-Lactamase and a Penicillin Target
Kelly, J.A.,Dideberg, O.,Charlier, P.,Wery, J.P.,Libert, M.,Moews, P.C.,Knox, J.R.,Duez, C.,Fraipont, C.,Joris, B.,al., et
(1986) Science 231: 1429
Two clinically-important beta-lactam antibiotics, cephalothin and cefotaxime, have been observed by X-ray crystallography bound to the reactive Ser62 of the D-alanyl-D-alanine carboxypeptidase/transpeptidase of Streptomyces sp. R61. Refinement of the ...
Two clinically-important beta-lactam antibiotics, cephalothin and cefotaxime, have been observed by X-ray crystallography bound to the reactive Ser62 of the D-alanyl-D-alanine carboxypeptidase/transpeptidase of Streptomyces sp. R61. Refinement of the two crystal structures produced R factors for 3 sigma (F) data of 0.166 (to 1.8 A) and 0.170 (to 2.0 A) for the cephalothin and cefotaxime complexes, respectively. In each complex, a water molecule is within 3.1 and 3.6 A of the acylated beta-lactam carbonyl carbon atom, but is poorly activated by active site residues for nucleophilic attack and deacylation. This apparent lack of good stereochemistry for facile hydrolysis is in accord with the long half-lives of cephalosporin intermediates in solution (20-40 h) and the efficacy of these beta-lactams as inhibitors of bacterial cell wall synthesis. Different hydrogen binding patterns of the two cephalosporins to Thr301 are consistent with the low cefotaxime affinity of an altered penicillin-binding protein, PBP-2x, reported in cefotaxime-resistant strains of Streptococcus pneumoniae, and with the ability of mutant class A beta-lactamases to hydrolyze third-generation cephalosporins.
Department of Molecular and Cell Biology, University of Connecticut, Storrs 06269-3125, USA.