Cloning Expression And Characterization Of The Gene Encoding IMPDH Of Streptococcus Suis Serotype 2

Streptococcus suis serotype 2 is the important pathogen of diseases in pigs and is a major cause of meningitis, septicemia, arthritis, and bronchopneumonia in young pigs and can cause meningitis in humans.With Streptococcus suis serotype 2, pathogenic, weakly pathogenic, and nonpathogenic strains can be found. The virulent factors that can be found include muraminidase-released protein(MRP), extracellular protein factor(EF), suilysin(SLY), New ORF2, fibronection(Fn). Give the lack of effective vaccines to control Streptococcus suis infection and the lack of a rapid and reliable molecular diagnostic assay to detect its infection, S. suis serotype 2 was sequenced partly in an effort to identify important virulence factors according to five main virulent factors: MRP, EF, SLY, New ORF2 and FBP in GenBank. The gene encoding IMPDH was found. The PCR product of the open reading frame was transformed into E.coli BL21 and the fusion protein of 48 kD was expressed. The recombinant protein was reactive with serum from pigs experimentally infected with virulent strains of S. suis type 2, suggesting that the protein is immunogenic. IMPDH activity straining confirmed that the protein had IMPDH function and can catalyze the rate-limiting reaction of GTP biosynthesis, the NAD-dependent reduction of IMP into XMP. Flow cytometry(FCM) revealed that the protein had apparent effect on HEp-2 cell cycle. 1 Cloning and Expression of Virulence-Associated Determinants of Streptococcus suis Serotype 2Analysis Gene sequence revealed that a new open reading frame that encoded a polypeptide of 319 amino acid residues with a calculated molecular mass of 33.5 kD was located between orf 2 and mrp of S.suis serotype 2. Second structure was analyzed by InterPro PHD DNAstar software, the PCR product of the open reading frame (2738 — 3694) was transformed into E.coli BL21 and the fusion protein of 48,000MW was expressed. At the amino acid level the deduced primary sequence...