Beta-lactamase of Bacillus licheniformis 749/C at 2 A resolution.Moews, P.C., Knox, J.R., Dideberg, O., Charlier, P., Frere, J.M.
(1990) Proteins 7: 156-171
- PubMed: 2326252
- DOI: 10.1002/prot.340070205
- PubMed Abstract:
- Crystallographic Comparison of Penicillin-Recognizing Enzymes
Knox, J.R.,Kelly, J.A.
(1989) Molecular Recognition. Chemical and Biochemical Problems --: 46
- 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.,Dusart, J.,Frere, J.M.,Ghuysen, J.M.
(1986) Science 231: 1429
Two crystal forms (A and B) of the 29,500 Da Class A beta-lactamase (penicillinase) from Bacillus licheniformis 749/C have been examined crystallographically. The structure of B-form crystals has been solved to 2 A resolution, the starting model for ...
Two crystal forms (A and B) of the 29,500 Da Class A beta-lactamase (penicillinase) from Bacillus licheniformis 749/C have been examined crystallographically. The structure of B-form crystals has been solved to 2 A resolution, the starting model for which was a 3.5 A structure obtained from A-form crystals. The beta-lactamase has an alpha + beta structure with 11 helices and 5 beta-strands seen also in a penicillin target DD-peptidase of Streptomyces R61. Atomic parameters of the two molecules in the asymmetric unit were refined by simulated annealing at 2.0 A resolution. The R factor is 0.208 for the 27,330 data greater than 3 sigma (F), with water molecules excluded from the model. The catalytic Ser-70 is at the N-terminus of a helix and is within hydrogen bonding distance of conserved Lys-73. Also interacting with the Lys-73 are Asn-132 and the conserved Glu-166, which is on a potentially flexible helix-containing loop. The structure suggests the binding of beta-lactam substrates is facilitated by interactions with Lys-234, Thr-235, and Ala-237 in a conserved beta-strand peptide, which is antiparallel to the beta-lactam's acylamido linkage; an exposed cavity near Asn-170 exists for acylamido substituents. The reactive double bond of clavulanate-type inhibitors may interact with Arg-244 on the fourth beta-strand. A very similar binding site architecture is seen in the DD-peptidase.
Department of Molecular and Cell Biology, University of Connecticut, Storrs 06269.