Transfer of Genes Coding for Apoproteins of Reaction Centre and Light-harvesting LH1 Complexes to Rhodobacter sphaeroides

Abstract

Several methods of introducing mobilizable cloning vectors by conjugation into the photosynthetic bacterium Rhodobacter sphaeroides have been examined. The efficiency of transfer was sufficiently high to enable a bank of Rb. sphaeroides genes in Escherichia coli to complement non-photosynthetic mutants of Rb. sphaeroides, thus providing a generally applicable method of isolating Rb. sphaeroides genes. With a mutant incapable of synthesizing reaction centres and light-harvesting LH1 complexes as a recipient, the transfer of puf genes encoding reaction centre and light-harvesting LH1 polypeptides was examined in some detail. The spectroscopic and electrophoretic properties of this mutant and the newly photosynthetic transconjugant strain were consistent with the efficient transfer and expression of puf genes.