Abstract: Total RNA was extracted from tachyzoites of RH strain of Toxoplasma gondii. The open reading frame of ROP11 gene was amplified by using a pair of specific primers designed according to the coding sequence of ROP11 gene （Accession No. DQ077905）. The RT-PCR product was digested by restriction enzyme EcoRⅠ and NotⅠ, and then ligated into a pGEX-6P-2 vector. The recombinant plasmid was transferred into E. coli XL-Blue. The positive clones was selected by colony PCR, and confirmed by the double restriction enzyme digestion and sequencing. The RT-PCR product was 1 548 bp. The recombinant plasmid was confirmed by colony PCR and double restriction enzyme digestion. Sequencing results showed that the obtained ROP11 gene was 1 548 bp （Accession No. KC456639）. There was a high sequence consistency （99%） between the obtained ROP11 gene sequence and the Toxoplasma ROP11 gene from GenBank. Bioinformatics analysis showed that the ROP11 protein （Mr 57 020） consisted of the signal peptide （amino acids 1-26）, 12 conservative domains, a serine/threonine protein kinase catalytic domain （amino acids 170-511）, and two potential N-glycosylation sites.

Key words: Toxoplasma gondii, Rhoptry protein 11, Prokaryotic expression, Bioinformatics analysis