Abstract: Methods are provided for producing recombinant proteins by utilizing expression vectors carrying nucleic acids encoding the proteins, and secretory signal sequences to direct the secretion of the proteins to the periplasm or extracellular medium. Expression vectors which encode a fusion protein comprising a carrier protein and the protein are also provided, as are host cells transformed with the expression vectors.

Abstract: A method of producing a protein or polypeptide, in which an expression vector that encodes a fusion protein comprising the protein or polypeptide peptide located carboxy-terminally to YebF, or a biologically active variant or portion thereof, is expressed in a suitable bacterial cell, to make the fusion protein. The method may further comprise the step of purifying the secreted fusion protein from the growth medium. The fusion protein may further comprise a peptide tag, or a protein cleavage site to separate the protein or polypeptide from the YebF portion, or the tag. Expression of a fusion protein into the culture medium provides a starting material for purification, in which the secreted fusion protein is relatively pure.