Complete amino acid sequence of the B875 light-harvesting protein of Rhodopseudomonas sphaeroides strain 2.4.1 : Comparison with R26.1 carotenoidless-mutant strain

• Published in: FEBS letters 1985-05, Vol.184 (2), p.231-236
• Main Authors: Theiler, Rolf, Suter, Franz, Pennoyer, Jeffrey D., Zuber, Herbert, Niederman, Robert A.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acid sequence Light-harvesting protein Photosynthetic membrane Polyacrylamide gel electrophoresis Rhodopseudomonas sphaeroides; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriochlorophylls - metabolism; Biological and medical sciences; Carotenoids - deficiency; Carotenoids - genetics; Cell structures and functions; Chloroplast, photosynthetic membrane and photosynthesis; Fundamental and applied biological sciences. Psychology; Light-Harvesting Protein Complexes; light-harvesting proteins; Macromolecular Substances; Molecular and cellular biology; Mutation; Photosynthesis; Photosynthetic Reaction Center Complex Proteins; Rhodobacter sphaeroides - enzymology; Rhodobacter sphaeroides - genetics; Rhodopseudomonas sphaeroides; Structure-Activity Relationship
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(85)80612-8

The complete amino acid sequence was determined for the α- and β-chains of the B875 light-harvesting protein purified from photosynthetic membranes of Rhodopseudomonas sphaeroides 2.4.1. The sequence of the B875-α-polypeptide was identical to that reported for the R26.1 carotenoidless mutant [(1985) Biochim. Biophys. Acta 806, 185-186] and contained 58 amino acid residues with a blocked methionine and a glutamic acid at the N- and C-termini, respectively. The B875-β-polypeptide contained 48 amino acid residues with alanine and phenylalanine as respective N- and C-termini; although otherwise identical, the leucine at position 29 in the wild-type strain was replaced by proline in the mutant. This radical amino acid substitution occurred within the central hydrophobic domain of the β-polypeptide chain and is thought to result in a weakening of the structure of the α/β heterodimer since it was not possible to isolate the intact pigment-protein complex from the R26.1 mutant strain.