OBJECTIVETo clone and express the Rv3871 gene related to the virulent protein secretion of Mycobacterium tuberculosis and analyze its molecular structure, function and homology using bioinformatic approach.

METHODSA pair of primers was designed to amplify the Rv3871 gene, which was subcloned into the prokaryotic plasmid pET32a(+). The recombinant plasmid was identified by sequence analysis and the expressed recombinant protein by SDS-PAGE. The structure, function and homology alignment of Rv3871 were analyzed comparatively against other mycobacteria.

RESULTSThe restriction fragments through molecular cloning matched perfectly in size with our prediction. The gene sequence was consistent with the corresponding sequence in GenBank. The expression protein was detected by SDS-PAGE with a molecular weight of 84 kD. Two FtsK/SpoE III domains were found by bioinformatic analysis. The homology results showed distinct differences between Rv3871 of the pathogenic M. tuberculosis and its counterparts in non-pathogenic mycobacteria.

CONCLUSIONMolecular cloning, expression and sequencing identify the structural and functional characteristics of Rv3871. The structural and functional differences of the gene between pathogenic and non-pathogenic mycobacteria identified by bioinformatics provide some evidence for the pathogenesis and drug targets of tuberculosis.