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
There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
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.
Copyright 2009 Elsevier Inc. All rights reserved.