Part of the accessory SecA2/SecY2 system specifically required to export SraP, a serine-rich repeat cell wall protein encoded upstream in the same operon. Part of the accessory SecA2/SecY2 protein translocation apparatus required to export cell wall protein SraP. No effect on cell growth, significantly reduces export of the cell wall protein SraP. The small amount that is exported seems to be glycosylated normally. Belongs to the accessory Sec system protein Asp3 family.