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
- Primary Citation of Related Structures:
- 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 which was a 3 ...
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.