Evolutionary diversification of the RomR protein of the invasive deltaproteobacterium, Bdellovibrio bacteriovorus

Lowry, Rebecca C.; Milner, David S.; Al-Bayati, Asmaa M.S.; Lambert, Carey; Francis, Vanessa I.; Porter, Steven L.; Sockett, R. E.

Abstract

Bdellovibrio bacteriovorus is a predatory deltaproteobacterium that encounters individual Gram-negative prey bacteria with gliding or swimming motility, and then is able to invade such prey cells via type IVa pilus-dependent mechanisms. Movement control (pili or gliding) in other deltaproteobacteria, such as the pack hunting Myxococcus xanthus, uses a response regulator protein, RomRMx (which dynamically relocalises between the cell poles) and a GTPase, MglAMx, previously postulated as an interface between the FrzMx chemosensory system and gliding or pilus-motility apparatus, to produce regulated bidirectional motility.In contrast, B. bacteriovorus predation is a more singular encounter between a lone predator and prey; contact is always via the piliated, non-flagellar pole of the predator, involving MglABd, but no Frz system. In this new study, tracking fluorescent RomRBd microscopically during predatory growth shows that it does not dynamically relocalise, in contrast to the M. xanthus protein; instead having possible roles in growth events. Furthermore, transcriptional start analysis, site-directed mutagenesis and bacterial two-hybrid interaction studies, indicate an evolutionary loss of RomRBd activation (via receiver domain phosphorylation) in this lone hunting bacterium, demonstrating divergence from its bipolar role in motility in pack-hunting M. xanthus and further evolution that may differentiate lone from pack predators.

Citation

Lowry, R. C., Milner, D. S., Al-Bayati, A. M., Lambert, C., Francis, V. I., Porter, S. L., & Sockett, R. E. (2019). Evolutionary diversification of the RomR protein of the invasive deltaproteobacterium, Bdellovibrio bacteriovorus. Scientific Reports, 9(1), 1-15. https://doi.org/10.1038/s41598-019-41263-5

• Journal Article Type: Article
• Acceptance Date: Feb 27, 2019
• Online Publication Date: Mar 21, 2019
• Publication Date: Mar 21, 2019
• Deposit Date: Mar 14, 2019
• Publicly Available Date: Mar 22, 2019
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 1
• Article Number: 5007
• Pages: 1-15
• DOI: https://doi.org/10.1038/s41598-019-41263-5
• Keywords: Multidisciplinary
• Public URL: https://nottingham-repository.worktribe.com/output/1648213
• Publisher URL: https://www.nature.com/articles/s41598-019-41263-5
• Additional Information: Received: 23 November 2018; Accepted: 27 February 2019; First Online: 21 March 2019; : The authors declare no competing interests.
• Contract Date: Mar 22, 2019