Structural and functional investigations of bdellovibrio bacteriovorus lifecycle proteins

[摘要] This thesis documents the findings undertaken on a diverse set of proteins that operate at distinct stages of the predatory lifecycle of Bdellovibrio bacteriovorus. In general, this work explores three major predatory lifecycle events: growth & metabolism, development & signalling and finally bdelloplast lysis & exit. In particular this thesis characterises four individual proteins (Bd2924, Bd1833, Bd0967 and Bd0314) that perform very different roles. In this study the three dimensional structure of Bd2924 (a putative acyl-CoA dehydrogenase) was determined, demonstrating an adaptation of the common acyl-CoA dehydrogenase fold, suggesting an important role beyond fatty acid β-oxidation. This work also presents the first structure of a multi-modular malic enzyme (Bd1833) and through extensive mutational and biochemical investigations, the mechanism behind allosteric regulation by acetyl-CoA was unpicked. In addition the structure of Bd0967 (a C-terminal processing protease) was solved, revealing a divergent fold that forms a large self-compartmentalised cavity. Furthermore, Bd0967 was determined to be involved in a developmental pathway that is interconnected with flagellin assembly. Finally, this study reveals how Bdellovibrio uses an adapted lysozyme (Bd0314), remodeled into a variant that now only accepts deacetylated cell wall sugars to lyse the bdelloplast at the end of the predatory lifecycle.

[发布机构] University:University of Birmingham;Department:School of Biosciences

[关键词] Q Science;QR Microbiology