Poster abstracts
Poster number 165 submitted by Anne Witzky
5-amino-pentanolylated elongation factor P influences cellular differentiation in Bacillus subtilis
Anne Witzky (Molecular Genetics and Center for RNA Biology, Ohio State University), Andrei Rajkovic (Molecular Cellular and Developmental Biology Program and Center for RNA Biology, Ohio State University), Katherine R. Hummels (Department of Biology, Indiana University), Sarah Erickson (Department of Chemistry, Ohio State University), Daniel B. Kearns (Department of Biology, Indiana University), Michael Ibba (Department of Microbiology, Ohio State University)
Abstract:
Bacillus subtilis is a gram-positive bacteria that exhibits two different types of motility: swimming and swarming. Although both movements require the same basic flagellar components, a number of regulatory factors have been identified that differentially impact swimming and swarming. For example, elongation factor P (EF-P) is a protein that is required for swarming but not swimming motility. EF-P is a universally conserved translation factor that relieves ribosomal pausing at polyproline motifs. In order to perform this function, EF-P requires post-translational modification. Although the position of the modification is conserved, the structure can vary widely between organisms. Here, we identify a novel EF-P post-translational modification, a 5-aminopentanol moiety, on Lys32. Based on the structure of the modification, it would appear to be derived from a polyamine. However, deletion of genes required for polyamine biosynthesis has no effect on modification, indicating that the substrate arises from another pathway. Mutation of Lys32 to an alanine prevents modification, abolishes swarming motility, and severely impairs EF-P dependent translation of a polyproline-GFP reporter construct in vivo. The Lys32Ala mutation also results in reduction in the levels of two polyproline containing flagellar components, likely explaining the requirement of EF-P for proper swarming. These findings not only establish a novel EF-P modification, but they also highlight its biochemical and physiological significance. Future studies will focus on identification of the genes required for EF-P modification in B. subtilis.
References:
Kearns DB, Chu F, Rudner R, Losick R (2004) Genes governing swarming in Bacillus subtilis and evidence for a phase variation mechanism controlling surface motility. Mol Microbiol 52: 357-369.
Lassak J, Wilson DN, Jung K (2016) Stall no more at polyproline stretches with the translation elongation factors EF-P and IF-5A. Mol Microbiol 99: 219-235.
Keywords: Translation, Elongation Factor P, Bacillus subtilis