Member of the two-component regulatory system PprA/PprB involved in biofilm formation by controlling the expression of many related genes including type IVb pili major subunit flp pilin, adhesin bapA or cupE fimbriae. Modulates also quorum-sensing signal production acting on both negative and positive modulators. Functions as a heme sensor histidine kinase which is autophosphorylated at a histidine residue and transfers its phosphate group to PprB. ATP + protein L-histidine = ADP + protein N-phospho-L-histidine. Autophosphorylated on His-156.