Figure 3

Phylogenetic tree, domain architectures and gene neighborhoods of proteins containing HNOB domains. Internal branches with RELL Bootstrap support >80% are indicated with red circles. Selected gene neighborhoods of HNOB domain proteins that provide contextual functional information are shown as box-arrows (The gene neighborhoods were determined as explained in the methods). The HNOB domain encoding genes are all colored dark orange, while other genes in the predicted operons are colored differently to match with the product they encode. All genes encoding proteins with a standalone HNOB domain are marked with red asterisks. Additionally, domain architectures are shown for all multidomain proteins with a HNOB domain and the products of their gene neighbors (latter are the indicated by green arrows). The globular domains are drawn approximately to scale, but low complexity linker regions are not shown (indicated by the "//"). Protein domain names generally follow accepted abbreviations. Additional domain abbreviations: TM: Transmembrane, MA: Methyl accepting chemotaxis receptor domain, HD-GYP: predicted cyclic diguanylate phosphodiesterase of the HD hydrolase superfamily, PP2C: PP2C-like phosphatase domain, HPT – Histidine Phosphotransfer domain, Receiver: Receiver domain of the two component system, alpha-CRD is a previously, unidentified α-helical receptor domain, with conserved aspartates, that is found in several prokaryotic chemotaxis receptors. C-helix: Conserved linker helix present at the C-terminus of the HNOBA domain. Gene names and species abbreviations are as in figure 1.