One of the proteins required for the normal export of preproteins out of the cell cytoplasm. It is a molecular chaperone that binds to a subset of precursor proteins, maintaining them in a translocation-competent state. It also specifically binds to its receptor secA (By similarity). SECB_YERPS YPTB0063 158 Protein-export protein secB secB MSEQNNTEMAFQIQRIYTKDISFEAPNAPQVFQQDWQPEVKLDLDTASSQLAEDVYEVVLRVTVTASLGEETAFLCEVQQGGIFSVAGIEGTQLAHCLGAYCPNILFPYARECITSLVSRGTFPQLNLAPVNFDALFMNYLQQQAEGEVEGVEQRQDA