Abstract：Setosphearia turcica is the causal agent of northern leaf blight of corn. We obtained a homologous fragment of Gβ gene from S. turcica, which was named as Stgb-1 and similar to homologus regions of other fungal Gβ genes. The 3’ cDNA end of Stgb-1 showed a 3’UTR containing 136 bp and a poly(A) tail containing nine A’s. Based on its high identity with CGB-1 in Cochliobolus heterostrophus, we designed specific primers which were corresponding to CGB-1 ORF and obtained succesfully the full length Stgb-1 ORF. It was 1056 bp and encoded 351 amino acid residues. The whole ORF was devided into 5 exons and 4 introns. The predicted protein sequence shared a high degree of sequence identity with Gβ protein from C. heterostrophus (100%), Cryphonectria parasitica (80%), Aspergillus fumigatus(81%). The sequence had been deposited in the GenBank/EBI Data Libraries under Accession No. EF407555. We used pET system to express Stgb-1. Results of SDS-PAGE and Western blotting showed that the recombinant protein with the calculated molecular mass of 40 kDa was expressed in E.coli. In conclusion, we had successfully cloned Gβ subunit gene of S. turcica and got the His-tag recombinant protein.
