4blm
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BETA-LACTAMASE OF BACILLUS LICHENIFORMIS 749(SLASH)C. REFINEMENT AT 2 ANGSTROMS RESOLUTION AND ANALYSIS OF HYDRATION
OverviewOverview
The crystallographic and molecular structure of the class A beta-lactamase, (penicillinase) of Bacillus licheniformis 749/C has been refined with, X-ray diffraction data to 2 A resolution. For the 27,330 data with F, greater than or equal to 3 sigma(F), the R factor is 0.15; for all 30,090, data, R is 0.16. The estimated co-ordinate error is 0.15 A. In the final, model, the deviation of covalent bonds and angles from ideality is 0.012 A, and 2.2 degrees, respectively. The model includes two molecules of 29,500, daltons each in the asymmetric unit of space group P2(1), 484 water, molecules and two tetrahedral buffer anions. Overlay of the two protein, molecules results in a root-mean-square difference of 0.17 A and 0.41 A, for alpha-carbon atoms and for all atoms, respectively. Twenty-six water, molecules fall within 0.25 A of matching water molecules associated with, the second protein molecule. The reactive Ser70 is on a turn of 3(10), helix at the N terminus of a longer alpha-helix (72-83). The, penicillin-binding site near this helix contains at least seven water, molecules. Upon penicillin entry, a water molecule in the oxyanion hole, hydrogen-bonded between the N terminus of helix (80-83) and beta-strand, (230-238), would be displaced by the oxygen atom of the beta-lactam, carbonyl group. An unexpelled molecule of water is proposed to be the, catalytic water required for penicillin hydrolysis. The water is, hydrogen-bonded to Glu166, a conserved residue in all beta-lactamases, and, it lies 3 A from the alpha-face of a previously modeled penicillin. The, position of the water-Glu166 pair is stabilized in the active site by a, cis peptide bond at Pro167.
About this StructureAbout this Structure
4BLM is a Single protein structure of sequence from Bacillus licheniformis with SO4 as ligand. The following page contains interesting information on the relation of 4BLM with [Penicillin-binding Proteins]. Active as Beta-lactamase, with EC number 3.5.2.6 Full crystallographic information is available from OCA.
ReferenceReference
Beta-lactamase of Bacillus licheniformis 749/C. Refinement at 2 A resolution and analysis of hydration., Knox JR, Moews PC, J Mol Biol. 1991 Jul 20;220(2):435-55. PMID:1856867
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