Rhodobacter capsulatus puf operon encodes a regulatory protein (PufQ) for bacteriochlorophyll biosynthesis.
AUTOR(ES)
Bauer, C E
RESUMO
Biosynthesis of the photochemical apparatus by purple nonsulfur photosynthetic bacteria is known to be inhibited by molecular oxygen and high light intensity. Polypeptides that bind bacteriochlorophyll (BChl) to form the light-harvesting I (LH-I) and reaction-center (RC) complexes are encoded by a single transcriptional unit termed the puf operon. In this investigation we demonstrate that the first structural gene in the puf operon (pufQ) of Rhodobacter capsulatus encodes a protein that is required for BChl biosynthesis and that there exists a linear relationship between the amount of pufQ expression and the level of BChl synthesis. Protein sequence similarity exists between PufQ and the region of RC polypeptides that are known to bind BChl and quinone. These observations suggest that pufQ may regulate BChl biosynthesis by a "carrier polypeptide" mechanism as originally proposed by Lascelles.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=282126Documentos Relacionados
- Identification of the PufQ protein in membranes of Rhodobacter capsulatus.
- Recombinant expression of the pufQ gene of Rhodobacter capsulatus.
- Structure of the puf operon of the obligately aerobic, bacteriochlorophyll alpha-containing bacterium Roseobacter denitrificans OCh114 and its expression in a Rhodobacter capsulatus puf puc deletion mutant.
- Structural and functional analysis of transcriptional control of the Rhodobacter capsulatus puf operon.
- Pleiotropic effects of localized Rhodobacter capsulatus puf operon deletions on production of light-absorbing pigment-protein complexes.
