A New Protein of the RC-LH1 Complex from the Phototrophic Purple Non-Sulfur Bacterium Rhodopseudomonas palustris

Abstract— In the RC-LH1 complex of Rhodopseudomonas (Rps.) palustris KM 286 (le5), a γ-protein, which was recently identified in the light-harvesting LH2 complex of this bacterium, was identified by proteomic analysis. For the first time, the method of adsorptive chromatography on hydroxyapatite was developed and applied to isolate RC-LH1. The bioinformatics analysis of Rps. palustris CGA009 (ATCC BAA-98) genome revealed a close location of the genes encoding α-, β-, and γ-proteins and similar functional groups in the γ-proteins of both complexes interacting with bacteriochlorophyll and the α- and β-proteins, which may indicate that γ-proteins have similar functions. The differences in the structure of the LH2 and LH1 complexes leave open the question of the localization of the γ-protein in RC-LH1, which requires further structural studies of this complex.