title: Comparative analysis of wolbachia genomes reveals streamlining and divergence of minimalist two-component systems.
abstract: Two-component regulatory systems are commonly used by bacteria to coordinate intracellular responses with environmental cues. These systems are composed of functional protein pairs consisting of a sensor histidine kinase and cognate response regulator. In contrast to the well-studied Caulobacter crescentus system, which carries dozens of these pairs, the streamlined bacterial endosymbiont Wolbachia pipientis encodes only two pairs: CckA/CtrA and PleC/PleD. Here, we used bioinformatic tools to compare characterized two-component system relays from C. crescentus, the related Anaplasmataceae species Anaplasma phagocytophilum and Ehrlichia chaffeensis, and 12 sequenced Wolbachia strains. We found the core protein pairs and a subset of interacting partners to be highly conserved within Wolbachia and these other Anaplasmataceae. Genes involved in two-component signaling were positioned differently within the various Wolbachia genomes, whereas the local context of each gene was conserved. Unlike Anaplasma and Ehrlichia, Wolbachia two-component genes were more consistently found clustered with metabolic genes. The domain architecture and key functional residues standard for two-component system proteins were well-conserved in Wolbachia, although residues that specify cognate pairing diverged substantially from other Anaplasmataceae. These findings indicate that Wolbachia two-component signaling pairs share considerable functional overlap with other α-proteobacterial systems, whereas their divergence suggests the potential for regulatory differences and cross-talk.
authors: Department of Biological Sciences, Florida International University, Miami, Florida 33199Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199.
authors: Steen
authors: S
authors: Christensen
authors: Department of Biological Sciences, Florida International University, Miami, Florida 33199Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199 Lserbus@fiu.edu.
authors: Laura Renee
authors: LR
authors: Serbus
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids; D019295:Computational Biology / Q000379:methods; D023061:Gene Order; D005798:Genes, Bacterial; D056426:Genetic Loci; D016680:Genome, Bacterial; D023281:Genomics / Q000379:methods; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009876:Operon; D054730:Protein Interaction Domains and Motifs; D016415:Sequence Alignment; D015398:Signal Transduction; D020577:Wolbachia / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000596:Amino Acids
keywords: Wolbachia; endosymbiont; genome organization; two-component signaling; α-proteobacteria