title: Episodic sitewise positive selection on the signal recognition particle protein Ffh in Actinobacteria.
abstract: In this work, we report a case of episodic sitewise positive selection acting on the highly conserved SRP protein Ffh in Actinobacteria. An elevated non-synonymous to synonymous mutation ratio (ω) was observed along the non-terminal branches of the species tree, which contained 11 Actinobacteria species, where positively selected residues were frequently observed within the signal sequence-binding domain. Together with the estimated lineage-specific ω ratios for several core components in the major protein translocation systems, our data suggest that this positive selection might be partially driven by the diversification of signal sequences.
authors.affiliation: Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, PR China.
authors.forename: Xue-Ling
authors.initials: XL
authors.lastname: Shen
authors.forename: Shan-Zhen
authors.initials: SZ
authors.lastname: Li
authors.forename: Yong-Quan
authors.initials: YQ
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
mesh_terms: D039903:Actinobacteria / Q000235:genetics*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D009154:Mutation; D021381:Protein Transport / Q000235:genetics; D012641:Selection, Genetic; D018271:Signal Recognition Particle / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D018271:Signal Recognition Particle