Artículo
Structural and mutational analyses of the Leptospira interrogans virulence-related heme oxygenase provide insights into its catalytic mechanism
Soldano, Anabel
; Klinke, Sebastian
; Otero, Lisandro Horacio
; Rivera, Mario; Catalano Dupuy, Daniela Luján
; Ceccarelli, Eduardo Augusto
Fecha de publicación:
08/2017
Editorial:
Public Library of Science
Revista:
Plos One
ISSN:
1932-6203
e-ISSN:
e0182535
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Heme oxygenase from Leptospira interrogans is an important virulence factor. During catalysis, redox equivalents are provided to this enzyme by the plastidic-type ferredoxin-NADP+ reductase also found in L. interrogans. This process may have evolved to aid this bacterial pathogen to obtain heme-iron from their host and enable successful colonization. Herein we report the crystal structure of the heme oxygenase-heme complex at 1.73 Å resolution. The structure reveals several distinctive features related to its function. A hydrogen bonded network of structural water molecules that extends from the catalytic site to the protein surface was cleared observed. A depression on the surface appears to be the H+ network entrance from the aqueous environment to the catalytic site for O2 activation, a key step in the heme oxygenase reaction. We have performed a mutational analysis of the F157, located at the above-mentioned depression. The mutant enzymes were unable to carry out the complete degradation of heme to biliverdin since the reaction was arrested at the verdoheme stage. We also observed that the stability of the oxyferrous complex, the efficiency of heme hydroxylation and the subsequent conversion to verdoheme was adversely affected. These findings underscore a long-range communication between the outer fringes of the hydrogen-bonded network of structural waters and the heme active site during catalysis. Finally, by analyzing the crystal structures of ferredoxin-NADP+ reductase and heme oxygenase, we propose a model for the productive association of these proteins.
Palabras clave:
Heme Oxygenase
,
Leptospira Interrogans
,
Crystal Structure
,
Iron Aquisition
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Articulos(IBR)
Articulos de INST.DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Articulos de INST.DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Articulos(IIBBA)
Articulos de INST.DE INVEST.BIOQUIMICAS DE BS.AS(I)
Articulos de INST.DE INVEST.BIOQUIMICAS DE BS.AS(I)
Citación
Soldano, Anabel; Klinke, Sebastian; Otero, Lisandro Horacio; Rivera, Mario; Catalano Dupuy, Daniela Luján; et al.; Structural and mutational analyses of the Leptospira interrogans virulence-related heme oxygenase provide insights into its catalytic mechanism; Public Library of Science; Plos One; 12; 8; 8-2017; 1-22; e0182535
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