The genes that encode the α and β polypeptides of the major light-harvesting complex of Rhodobacter sphaeroides, B800–850, have been cloned and sequenced through the use of oligonucleotides based upon the known polypeptide sequences. These genes, pucA and B, are transcribed in the order B, A, are of 150 and 164 nucleotides respectively, and are separated by a spacer region of 14 nucleotides. Transfer of these genes to mutant M21 lacking the B800–850 complex has been accomplished and absorbance spectra of recombinant strains M2181 and M2184 show that expression of pucA and B is comparable to levels found in the wild type.
