Abolition of magnesium chelatase activity by the gun5 mutation and reversal by Gun4.
FEBS Lett
; 585(1): 183-6, 2011 Jan 03.
Article
em En
| MEDLINE
| ID: mdl-21110975
ABSTRACT
The chlorophyll-deficient gun5-1 and cch Arabidopsis mutants carry single point mutations in the CHLH subunit of the magnesium chelatase enzyme, which catalyses the first committed step of chlorophyll biosynthesis. Recombinant Synechocystis ChlH subunits carrying the gun5-1 or cch mutations are inactive in Mg-chelatase assays, despite being able to bind both substrate and product, and retaining a capacity to form a ChlH-ChlI-ChlD Mg-chelatase complex. These mutant subunits act as inhibitors of ChlH, showing that the ChlH-porphyrin complex associates reversibly with the ChlI and D subunits during the catalytic cycle. This inhibition is reversed upon addition of Gun4.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Arabidopsis
/
Peptídeos e Proteínas de Sinalização Intracelular
/
Liases
/
Mutação
Idioma:
En
Revista:
FEBS Lett
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Reino Unido