3blm

REFINED CRYSTAL STRUCTURE OF BETA-LACTAMASE FROM STAPHYLOCOCCUS AUREUS PC1 AT 2.0REFINED CRYSTAL STRUCTURE OF BETA-LACTAMASE FROM STAPHYLOCOCCUS AUREUS PC1 AT 2.0

Structural highlights 3blm is a 1 chain structure with sequence from "micrococcus_aureus"_(rosenbach_1884)_zopf_1885 "micrococcus aureus" (rosenbach 1884) zopf 1885. This structure supersedes the now removed PDB entry 1blm. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Activity: Beta-lactamase, with EC number 3.5.2.6 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The crystal structure of a class A beta-lactamase from Staphylococcus aureus PC1 has been refined at 2.0 A resolution. The resulting crystallographic R-factor (R = sigma h parallel Fo[-]Fc parallel/sigma h[Fo], where [Fo] and [Fc] are the observed and calculated structure factor amplitudes, respectively), is 0.163 for the 17,547 reflections with I greater than or equal to 2 sigma (I) within the 8.0 A to 2.0 A resolution range. The molecule consists of two closely associated domains. One domain is formed by a five-stranded antiparallel beta-sheet with three helices packing against a face of the sheet. The second domain is formed mostly by helices that pack against the second face of the sheet. The active site is located in the interface between the two domains, and many of the residues that form it are conserved in all known sequences of class A beta-lactamases. Similar to the serine proteases, an oxyanion hole is implicated in catalysis. It is formed by two main-chain nitrogen atoms, that of the catalytic seryl residue, Ser70, and that of Gln237 on an edge beta-strand of the major beta-sheet. Ser70 is interacting with another conserved seryl residue, Ser130, located between the two ammonium groups of the functionally important lysine residues, Lys73 and Lys234. Such intricate interactions point to a possible catalytic role for this second seryl residue. Another key catalytic residue is Glu166. There are several unusual structural features associated with the active site. (1) A cis peptide bond has been identified between the catalytic Glu166 and Ile167. (2) Ala69 and Leu220 have strained phi, psi dihedral angles making close contacts that restrict the conformation of the active site beta-strand involved in the formation of the oxyanion hole. (3) A buried aspartate residue, the conserved Asp233, is located next to the active site Lys234. It is interacting with another buried aspartyl residue, Asp246. An internal solvent molecule is also involved, but the rest of its interactions with the protein indicate it is not a cation. (4) Another conserved aspartyl residue that is desolvated is Asp131, adjacent to Ser130. Its charge is stabilized by interactions with four main-chain nitrogen atoms. (5) An internal cavity underneath the active site depression is filled with six solvent molecules. This, and an adjacent cavity occupied by three solvent molecules partially separate the omega-loop associated with the active site from the rest of the protein.(ABSTRACT TRUNCATED AT 250 WORDS) Refined crystal structure of beta-lactamase from Staphylococcus aureus PC1 at 2.0 A resolution.,Herzberg O J Mol Biol. 1991 Feb 20;217(4):701-19. PMID:2005620 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Beta-lactamase 3D structures

spinqualitylabelsall models 3blm, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image