Open AccessEffect of uncoupler on assembly pathway for pigment-binding protein of bacterial photosynthetic membranes
Author(s) -
Roland Dierstein,
Gerhart Drews
Publication year - 1986
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.168.1.167-172.1986
Subject(s) - biology , periplasmic space , rhodobacter , biochemistry , inner membrane , transmembrane protein , membrane protein , bacterial outer membrane , spheroplast , membrane , chemiosmosis , biophysics , escherichia coli , atp synthase , receptor , mutant , enzyme , gene
The uncoupler carbonylcyanide m-chlorophenylhydrazone (CCCP) was used to investigate membrane protein assembly in the phototrophic bacterium Rhodobacter capsulatus. As found for Escherichia coli (T. Date, G. Zwizinsky, S. Ludmerer, and W. Wickner, Proc. Natl. Acad. Sci. 77:827-831, 1980) and mitochondrial proteins (N. Nelson and G. Schatz, Proc. Natl. Acad. Sci. USA 76:4365-4369, 1979), assembly across the bacterial photosynthetic membranes was sensitive to CCCP. At uncoupler concentrations which were sufficient to block the export of the periplasmic cytochrome c2 and an outer membrane protein, the integration of pigment-binding protein into the photosynthetic apparatus was abolished. The unassembled protein was detected on the inner surface of the intracytoplasmic membrane. After inactivation of CCCP, accumulated protein continued insertion into the membrane. The data suggest that after binding to the cytoplasmic face of the membrane, translocation of protein into a transmembrane orientation takes place, which is a prerequisite for the formation of a functional pigment-protein complex.