1m22: Difference between revisions
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{{STRUCTURE_1m22| PDB=1m22 | SCENE= }} | |||
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'''X-ray structure of native peptide amidase from Stenotrophomonas maltophilia at 1.4 A''' | '''X-ray structure of native peptide amidase from Stenotrophomonas maltophilia at 1.4 A''' | ||
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[[Category: Labahn, J.]] | [[Category: Labahn, J.]] | ||
[[Category: Neumann, S.]] | [[Category: Neumann, S.]] | ||
[[Category: | [[Category: Covered double layers of alpha helices on top and bottom]] | ||
[[Category: | [[Category: Eleven-stranded beta sheet]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 00:32:27 2008'' | |||
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Revision as of 00:32, 3 May 2008
X-ray structure of native peptide amidase from Stenotrophomonas maltophilia at 1.4 A
OverviewOverview
The peptide amidase from Stenotrophomonas maltophilia catalyses predominantly the hydrolysis of the C-terminal amide bond in peptide amides. Peptide bonds or amide functions in amino acid side-chains are not hydrolysed. This specificity makes peptide amidase (Pam) interesting for different biotechnological applications. Pam belongs to the amidase signature (AS) family. It is the first protein within this family whose tertiary structure has been solved. The structure of the native Pam has been determined with a resolution of 1.4A and in complex with the competitive inhibitor chymostatin at a resolution of 1.8A. Chymostatin, which forms acyl adducts with many serine proteases, binds non-covalently to this enzyme.Pam folds as a very compact single-domain protein. The AS sequence represents a core domain that is covered by alpha-helices. This AS domain contains the catalytic residues. It is topologically homologous to the phosphoinositol phosphatase domain.The structural data do not support the recently proposed Ser-Lys catalytic dyad mechanism for AS enzymes. Our results are in agreement with the role of Ser226 as the primary nucleophile but differ concerning the roles of Ser202 and Lys123: Ser202, with direct contact both to the substrate molecule and to Ser226, presumably serves as an acid/bases catalyst. Lys123, with direct contact to Ser202 but no contact to Ser226 or the substrate molecule, most likely acts as an acid catalyst.
About this StructureAbout this Structure
1M22 is a Single protein structure of sequence from Stenotrophomonas maltophilia. Full crystallographic information is available from OCA.
ReferenceReference
An alternative mechanism for amidase signature enzymes., Labahn J, Neumann S, Buldt G, Kula MR, Granzin J, J Mol Biol. 2002 Oct 4;322(5):1053-64. PMID:12367528 Page seeded by OCA on Sat May 3 00:32:27 2008