The identification of a highly conserved, immunologically accessible antigen at the surface of Neisseria facilitates treatment, prophylaxis, and diagnosis of Neisseria diseases. This antigen is highly resistant to Proteinase K and has an apparent molecular weight of 22 kDa on SDS-PAGE. Specific polynucleotides encoding proteins of this class have been isolated from three Neisseria meningitidis strains and from one Neisseria gonorrhoeae strain. These polynucleotides have been sequenced, and the corresponding full-length amino acid sequences of the encoded polypeptides have been deduced. Recombinant DNA methods for the production of the Neisseria surface protein, and antibodies that bind to this protein are also disclosed.