title: Role of inter-domain cavity in the attachment of the orange carotenoid protein to the phycobilisome core and to the fluorescence recovery protein.
abstract: Using molecular modeling and known spatial structure of proteins, we have derived a universal 3D model of the orange carotenoid protein (OCP) and phycobilisome (PBS) interaction in the process of non-photochemical PBS quenching. The characteristic tip of the phycobilin domain of the core-membrane linker polypeptide (LCM) forms the attachment site on the PBS core surface for interaction with the central inter-domain cavity of the OCP molecule. This spatial arrangement has to be the most advantageous one because the LCM, as the major terminal PBS-fluorescence emitter, accumulates energy from the most other phycobiliproteins within the PBS before quenching by OCP. In agreement with the constructed model, in cyanobacteria, the small fluorescence recovery protein is wedged in the OCP's central cavity, weakening the PBS and OCP interaction. The presence of another one protein, the red carotenoid protein, in some cyanobacterial species, which also can interact with the PBS, also corresponds to this model.
authors.affiliation: a Faculty of Biology , Lomonosov State University , 119234 , Lenin Hills 1/12, Moscow , Russia.
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Zlenko
authors.affiliation: a Faculty of Biology , Lomonosov State University , 119234 , Lenin Hills 1/12, Moscow , Russia.
authors.forename: Pavel M
authors.initials: PM
authors.lastname: Krasilnikov
authors.affiliation: b A.N. Bakh Institute of Biochemistry RAS , 119071 , Leninsky Prospekt 33/2, Moscow , Russia.
authors.forename: Igor N
authors.initials: IN
authors.lastname: Stadnichuk
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D019906:Nuclear Magnetic Resonance, Biomolecular; D045524:Phycobilisomes / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs
chemical_list: D001426:Bacterial Proteins; D045524:Phycobilisomes
keywords: LCM–polypeptide; allophycocyanin; fluorescence recovery protein; orange carotenoid protein; phycobilisome(s); red carotenoid protein