2BLM

BETA-LACTAMASE OF BACILLUS LICHENIFORMIS 749(SLASH)C AT 2 ANGSTROMS RESOLUTION

Summary for 2BLM

• Entry DOI: 10.2210/pdb2blm/pdb
• Descriptor: BETA-LACTAMASE (1 entity in total)
• Functional Keywords: hydrolase(acting in cyclic amides)
• Biological source: Bacillus licheniformis
• Cellular location: Cell membrane; Lipid-anchor (Probable): P00808
• Total number of polymer chains: 2
• Total formula weight: 59084.87

Authors

Moews, P.C.,Knox, J.R.,Dideberg, O. (deposition date: 1990-02-02, release date: 1990-10-15, Last modification date: 2024-02-14)

Primary citation

Moews, P.C.,Knox, J.R.,Dideberg, O.,Charlier, P.,Frere, J.M.
Beta-lactamase of Bacillus licheniformis 749/C at 2 A resolution.
Proteins, 7:156-171, 1990

PubMed Abstract: 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.

PubMed: 2326252
DOI: 10.1002/prot.340070205

Experimental method

X-RAY DIFFRACTION (2 Å)