Required for the formation of functionally normal spores. Could be involved in the establishment of normal spore coat structure and/or permeability, which allows the access of germinants to their receptor. Expressed during sporulation, around the time of spore coat synthesis and assembly, in mother cell compartment. Expression is sigma K-dependent and negatively regulated by GerE. Belongs to the GerPA/GerPF family. Extended N-terminus.