Photox, a novel actin-targeting mono-ADP-ribosyltransferase from Photorhabdus luminescens.
J Biol Chem
; 285(18): 13525-34, 2010 Apr 30.
Article
em En
| MEDLINE
| ID: mdl-20181945
ABSTRACT
Photorhabdus luminescens is a pathogenic bacterium that produces many toxic proteins. The mono-ADP-ribosyltransferases (mARTs) are an enzyme class produced by numerous pathogenic bacteria and participate in disease in plants and animals, including humans. Herein we report a novel mART from P. luminescens called Photox. This 46-kDa toxin shows high homology to other actin-targeting mARTs in hallmark catalytic regions and a similar core catalytic fold. Furthermore, Photox shows in vivo cytotoxic activity against yeast, with protection occurring when catalytic residues are substituted with alanine. In vitro, enzymatic activity (k(cat), 1680 +/- 75 min(-1)) is higher than that of the related iota toxin, and diminishes by nearly 14,000-fold following substitution of the catalytic Glu (E355A). This toxin specifically ADP-ribosylates monomeric alpha-skeletal actin and nonmuscle beta- and gamma-actin at Arg(177), inhibiting regular polymerization of actin filaments. These results indicate that Photox is indeed an ADP-ribosyltransferase, making it the newest member of the actin-targeting mART family.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Toxinas Bacterianas
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Citoesqueleto de Actina
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Actinas
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ADP Ribose Transferases
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Photorhabdus
Limite:
Animals
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article