[Homologous analysis of Streptococcus suis srt gene and prokaryotic expression of srtA].
OBJECTIVE
To elucidate the distribution of srt gene in the genome of S.suis 05ZYH33, prokaryotically express Sortase A and analyze its antigenicity.


METHODS
Homologous genes encoding sortase family members were analyzed, and then the srtA gene of S.suis was cloned and sequenced. The recombinant protein was analyzed by SDS-PAGE and Western blot. The mice were immunized with recombinant protein and the antibody titer was determined by indirect ELISA.


RESULTS
All the putative srt genes in the genome of 05ZYH33 were analyzed. Six genes were found to be homologous to srt of S.suis isolated in Japan. The predicted srtA and sortase-like proteins were members of Class A of sortase family while srtBCD and srtE belonged to Class B. Western blot analysis showed that the recombinant protein was reactive to with the serum from the rabbits infected with a virulent strain of S.suis Type 2. The antibody titer in blood serum reached 1:6 400 after immunization with recombinant protein four times.


CONCLUSIONS
Compared with the isolated strain from Japan a new putative srt gene was found in 05ZYH33. The srtA gene was successfully expressed in prokaryotic system and the recombinant protein showed specific antigenicity, which is important for future research of the function of Sortase.
Dong
Ya-qing
YQ
College of Veterinary Medicine, Nanjing Agriculture University, Nanjing 210095, China. yaqingdong1980@163.com
Wang
Chang-jun
CJ
Zheng
Feng
F
Pan
Xiu-zhen
XZ
Fan
Hong-jie
HJ
Tang
Jia-qi
JQ
D019881:Aminoacyltransferases / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015153:Blotting, Western; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D016680:Genome, Bacterial / Q000235:genetics; D051379:Mice; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D017011:Streptococcus suis / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*
D001426:Bacterial Proteins; D011994:Recombinant Proteins; C509821:sortase B; C509822:sortase C; C509823:sortase D; C509824:sortase E; D019881:Aminoacyltransferases; C120542:sortase A; D003546:Cysteine Endopeptidases