Novel Two-Component System-Like Elements Reveal Functional Domains Associated with Restriction-Modification Systems and paraMORC ATPases in Bacteria.

Two-component systems (TCS) are important types of machinery allowing for efficient signal recognition and transmission in bacterial cells. The majority of TCSs utilized by bacteria is composed of a sensor histidine kinase (HK) and a cognate response regulator (RR). In the present study, we report two newly predicted protein domains-both to be included in the next release of the Pfam database: Response_reg_2 (PF19192) and HEF_HK (PF19191)-in bacteria which exhibit high structural similarity, respectively, with typical domains of RRs and HKs.