BACTERIAL SURFACE PROTEIN EXPRESSION

摘要

This invention provides a bacterium having an S-layer wherein the bacterium's S-layer protein gene contains one or more sequences encoding one or more heterologous polypeptides and, said S-layer is a fusion product of the S-layer protein and said heterologous polypeptide. Preferably, the bacterium is a Caulobacter which may be cultured as a film in a bioreactor or may be administered as a live vaccine. The heterologous polypeptide may be an enzyme, a ligand, an antigen or another functional sequence of amino acids. This invention also provides a method of expressing and presenting a functional polypeptide which comprises cloning a gene sequence for said polypeptide in-frame into the S-layer protein gene of Caulobacter and, culturing said Caulobacter having an S-layer which is a fusion product of the S-layer protein and the polypeptide. This invention also provides a DNA sequence comprising all or substantially all of a Caulobacter S-layer protein gene containing one or more heterologous sequences encoding restriction endonuclease sites which heterologous sequences preserve the translational frame of said gene to facilitate insertion of further heterologous sequences into said gene. This invention also provides a substantially purified DNA molecule essentially consisting of all orsubstantially all of a Caulobacter crescentus S-protein gene sequence.