REGB_RHOSH Protein prrB prrB MILGPDGILNRDTRGDWWRLRTLILLRWMAVAGQLAAIVVTDWYLGVRLPMGLCFMAVGASVIANVIATFVFPQNRRLTEFQALMILLFDLTQLSFLLFLTGGLTNPFALLILAPVTISGVALDVRTTVILGAIAIGLLTFTAYFHLPLILADGSSLSVPRMFEFGFWLAIVIGILFLGLYSRRVAIEIRSMSDALLATQMALDREQKLTDLGGVVAAAAHELGTPLATIKLVSSELAEELSEQPALRDDADVIREQADRCRDILRSMGRAGKDDLQMRQGPLGEVLREAAEPHVGRGKRVEFDLYPSRGGDERQPVILRRPEVIHGVRNLIQNAVDFARSTVWIDGEWTGDRIAIRIVDDGEGYPPAIIGRIGDPFVRQRRAEESQSRRPGYEGMGLGLFIAKTLLERSGAELSFANAADPFLRSHERPERCGAIVEVIWPVDRLVVVRNAPLGENVLIQT 462 Member of the two-component regulatory system RegB/RegA. Involved in the positive regulation of photosynthesis gene expression in response to anaerobiosis. Also involved in positive regulation of the cbbI and cbbII Calvin cycle CO2 fixation operons, as well as in regulation of expression of genes involved in alternative CO2 fixation pathways. Phosphorylates RegA/PrrA. Sensor histidine kinase regB regB