Abstract: The ompH gene encoding mature outer membrane protein H (OmpH) without a signal peptide was isolated from genomic DNA of avian P. multocida type strain X-73 by PCR.The BamHⅠand XhoⅠ digested PCR product was cloned into prokaryotic expression vector pMAL-p2X to provide a recombinant plasmid pMAL-p2X-ompH.The fusion protein of MBP-OmpH was expressed in E.coli BL21 harboring the recombinant plasmid pMAL-p2X-ompH by IPTG induction,and the recombinant protein was detected with SDS-PAGE.The sequence analysis showed that the ompH gene coding the mature protein was 1 002 bp in length,and completely identical to the previously reported ompH gene of strain X-73;while the SDS-PAGE showed that a single protein band with molecular weight of 78 kDa in E. coli after IPTG inducing.The recombinant protein OmpH can be used as positive control on development subunit vaccine for fowl cholera.

Key words: avian pasteurella multocida, prokaryotic expression, ompH gene, fusion protein