title: Phylogenomic and structural modeling analyses of the PsbP superfamily reveal multiple small segment additions in the evolution of photosystem II-associated PsbP protein in green plants.
abstract: PsbP is a thylakoid lumen protein involved in oxygen evolution in photosystem II (PSII) in green plants. Genomic analysis identified a number of PsbP homologs in plants, algae, and cyanobacteria. To analyze the transition of cyanobacterial PsbO/U/V complex to PsbO/P/Q complex in green plants, the evolutionary history of the PsbP superfamily was reconstructed. Phylogenetic analyses suggested that PsbP homologs be classified into eight major families (A-H), which were also characterized by specific insertion/deletion of short segments, as found by sequence alignment and homology modeling. Family A represented authentic PsbP proteins involved in oxygen evolution. The cyanobacterial PsbP and plant/algal PPL (Family H), having the simplest structure, should be considered as the root of all other families of PsbP, which subsequently gained various short, family-specific structural motifs during diversification of PsbP families. Interestingly, segments specific to Family A proteins were found arranged as a ring surrounding the modeled Arabidopsis PsbP protein. These results suggest that Family A-specific additions of short segments played a decisive role in the transition of PsbO/U/V to PsbO/P/Q complex in green plants.
authors: Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan. naokisat@bio.c.u-tokyo.ac.jp
authors: Naoki
authors: N
authors: Sato
mesh_terms: D000595:Amino Acid Sequence; D001499:Bayes Theorem; D000458:Cyanobacteria / Q000145:classification / Q000235:genetics; D056890:Eukaryota / Q000145:classification / Q000235:genetics; D019143:Evolution, Molecular; D054643:INDEL Mutation; D016013:Likelihood Functions; D008958:Models, Molecular; D008969:Molecular Sequence Data; D045332:Photosystem II Protein Complex / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D010944:Plants / Q000145:classification / Q000235:genetics*; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein
chemical_list: D045332:Photosystem II Protein Complex; D010940:Plant Proteins