1s2b

Structure of SCP-B the first member of the Eqolisin family of Peptidases to have its structure determined

spinqualitylabelsall models 1s2b, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1s2b is a 1 chain structure with sequence from Scytalidium lignicola. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.1Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function PRTB_SCYLI 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 molecular structure of the pepstatin-insensitive carboxyl peptidase from Scytalidium lignicolum, formerly known as scytalidopepsin B, was solved by multiple isomorphous replacement phasing methods and refined to an R factor of 0.230 (R(free) = 0.246) at 2.1-A resolution. In addition to the structure of the unbound peptidase, the structure of a product complex of cleaved angiotensin II bound in the active site of the enzyme was also determined. We propose the name scytalidocarboxyl peptidase B (SCP-B) for this enzyme. On the basis of conserved, catalytic residues identified at the active site, we suggest the name Eqolisin for the enzyme family. The previously uninvestigated SCP-B fold is that of a beta-sandwich; each sheet has seven antiparallel strands. A tripeptide product, Ala-Ile-His, bound in the active site of SCP-B has allowed for identification of the catalytic residues and the residues in subsites S1, S2, and S3, which are important for substrate binding. The most likely hydrolytic mechanism involves nucleophilic attack of a general base (Glu-136)-activated water (OH(-)) on the si-face of the scissile peptide carbonylcarbon atom to form a tetrahedral intermediate. Electrophilic assistance and oxyanion stabilization is provided by the side-chain amide of Gln-53. Protonation of the leaving-group nitrogen is accomplished by the general acid function of the protonated carboxyl group of Glu-136. The molecular structure and catalytic mechanism of a novel carboxyl peptidase from Scytalidium lignicolum.,Fujinaga M, Cherney MM, Oyama H, Oda K, James MN Proc Natl Acad Sci U S A. 2004 Mar 9;101(10):3364-9. Epub 2004 Mar 1. PMID:14993599 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Pepsin

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