Open AccessIsolation of mutants and genes involved in cytochromes c biosynthesis in Rhodobacter capsulatus
Author(s) -
Robert G. Kranz
Publication year - 1989
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.171.1.456-464.1989
Subject(s) - rhodobacter , biology , complementation , cosmid , mutant , gene , cytochrome , genetics , biochemistry , microbiology and biotechnology , enzyme
Mutants of the photosynthetic bacterium Rhodobacter capsulatus that have combined deficiencies in the cytochrome b/c1 complex and other c-type cytochromes have been isolated. These mutants were unable to grow anaerobically in the light or dark but could grow aerobically. Cosmids with R. capsulatus wild-type DNA that complement the mutants have been used to construct genetic and physical maps of the affected genes. Complementation profiles with Tn5 and mini-Mu insertions in these cosmids and subcloned fragments from them indicated that at least three genes (called helA, helB, and helC) are involved in the defects in cytochromes c biosynthesis. The genes are clustered, and helC is transcribed away from helA and helB. Stable insertion mutants in each gene were constructed. It is postulated that helA, helB, and helC are involved in posttranslational processing during cytochromes c synthesis.