English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/27440
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

Mutants that alter the covalent structure of catalase hydroperoxidase II from Escherichia coli

AuthorsMaté, María J. ; Sevinc, M. Serdal; Hu, Bei; Bujons Vilàs, Jordi ; Bravo, Jerónimo ; Switala, Jack; Ens, Werner; Loewen, Peter C.; Fita, Ignacio
Issue Date24-Sep-1999
PublisherAmerican Society for Biochemistry and Molecular Biology
CitationJournal of Biological Chemistry 274(39): 27717-27725 (1999)
AbstractThe three-dimensional structures of two HPII variants, V169C and H392Q, have been determined at resolutions of 1.8 and 2.1 A, respectively. The V169C variant contains a new type of covalent bond between the sulfur atom of Cys(169) and a carbon atom on the imidazole ring of the essential His(128). This variant enzyme has only residual catalytic activity and contains heme b. The chain of water molecules visible in the main channel may reflect the organization of the hydrogen peroxide substrates in the active enzyme. Two alternative mechanisms, involving either compound I or free radical intermediates, are presented to explain the formation of the Cys-His covalent bond. The H392Q and H392E variants exhibit 75 and 25% of native catalytic activity, respectively. The Gln(392) variant contains only heme b, whereas the Glu(392) variant contains a mixture of heme b and cis and trans isomers of heme d, suggesting of a role for this residue in heme conversion. Replacement of either Gln(419) and Ser(414), both of which interact with the heme, affected the cis:trans ratio of spirolactone heme d. Implications for the heme oxidation mechanism and the His-Tyr bond formation in HPII are considered.
Description9 pages, 6 figures, 3 tables.-- PMID: 10488114 [PubMed].
Publisher version (URL)http://dx.doi.org/10.1074/jbc.274.39.27717
URIhttp://hdl.handle.net/10261/27440
DOI10.1074/jbc.274.39.27717
ISSN0021-9258
E-ISSN1083-351X
Appears in Collections:(IQAC) Artículos
Files in This Item:
There are no files associated with this item.
Show full item record
Review this work
 

Related articles:


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.