Phyletic distribution and conservation of the bacterial transcription termination factor Rho

• DOI: 10.1099/mic.0.067462-0
• Publication Date: 2013-05-24T05:11:46Z
• Authors: François D’Heygère; Makhlouf Rabhi; Marc Boudvillain
• Keywords: Bacterial genome size; Bacterial transcription; Conserved sequence; Prokaryote

Transcription termination factor Rho is a ring-shaped, ATP-dependent molecular motor that targets hundreds of transcription units in Escherichia coli. Interest was renewed recently on the realization this essential involved multiple interactions and cellular processes protect E. coli genome regulate its expression global scale. Yet it currently unknown if (and how) Rho-dependent mechanisms are conserved throughout bacterial kingdom. Here, we mined public databases to assess distribution, structural conservation across phyla. We found rho present more than 90 % sequenced genomes, although Cyanobacteria, Mollicutes fraction Firmicutes totally devoid rho. Genomes lacking tend be small AT-rich often belong species with parasitic/symbiotic lifestyles (such as Mollicutes). By contrast, large GC-rich such those Actinobacteria, contain duplicates and/or encode proteins bear insertion domains function(s). Notwithstanding, most sequences taxa canonical RNA-binding ATP hydrolysis signature motifs, feature suggestive largely mechanism(s) action. Mutations impair binding bicyclomycin ~5 sequences, implying from diverse ecosystems have developed resistance against natural antibiotic. Altogether, these findings assert function widespread among bacteria suggest plays particularly relevant role complex genomes adaptation changing environments.