title: Three-dimensional structure of carboxypeptidase T from Thermoactinomyces vulgaris in complex with N-BOC-L-leucine.
abstract: The 3D structure of recombinant bacterial carboxypeptidase T (CPT) in complex with N-BOC-L-leucine was determined at 1.38 Å resolution. Crystals for the X-ray study were grown in microgravity using the counter-diffusion technique. N-BOC-L-leucine and SO4(2-) ion bound in the enzyme active site were localized in the electron density map. Location of the leucine side chain in CPT-N-BOC-L-leucine complex allowed identification of the S1 subsite of the enzyme, and its structure was determined. Superposition of the structures of CPT-N-BOC-L-leucine complex and complexes of pancreatic carboxypeptidases A and B with substrate and inhibitors was carried out, and similarity of the S1 subsites in these three carboxypeptidases was revealed. It was found that SO4(2-) ion occupies the same position in the S1' subsite as the C-terminal carboxy group of the substrate.
authors.affiliation: Shubnikov Institute of Crystallography, Russian Academy of Sciences, Moscow, Russia. inna@ns.crys.ras.ru
authors.forename: V I
authors.initials: VI
authors.lastname: Timofeev
authors.forename: S A
authors.initials: SA
authors.lastname: Kuznetsov
authors.forename: V Kh
authors.initials: VKh
authors.lastname: Akparov
authors.forename: G G
authors.initials: GG
authors.lastname: Chestukhina
authors.forename: I P
authors.initials: IP
authors.lastname: Kuranova
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002268:Carboxypeptidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D021621:Imaging, Three-Dimensional; D007930:Leucine / Q000031:analogs & derivatives* / Q000737:chemistry; D008958:Models, Molecular; D011487:Protein Conformation; D056509:Thermoactinomyces / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D002268:Carboxypeptidases; C076614:CPT protein, Thermoactinomyces vulgaris; D007930:Leucine