Suggested to be part of an ABC transporter complex YydIJ involved in export of the modified peptide YydF (Probable). Responsible for energy coupling to the transport system (By similarity). The complex is composed of two ATP-binding proteins (YydI), two transmembrane proteins (YydJ). Transcriptionally repressed by rok (PubMed:15743949), this was not found to be the case in another study (PubMed:17921301). Up-regulates expression of the LiaRS two-component regulatory system; this effect is more pronounced on modified competence medium than on rich or sporulation medium. Belongs to the ABC transporter superfamily.