Immunogen sequence: ECSIRLPKAA KTPLKIHPLV RLPLATIVKD LVAQAPLKPK TPRGTKTPIN RNQLSQNRGL GGIMVKRAYE TMAGAGVPFS ANGRPLASGI RSSSQPAAKR QKLNPADAPN PVVFVATKDT RALRKALTHL EMRRAARRPN LPLKVKPT. This gene encodes a protein that has been identified as a component of