Figure 1

T. gondii cdk7, cyclinH and mat1 genes shares functional homology with S. cerevisiae kin28, ccl1 and tfb3 genes respectively.

(A) Schematic diagrams of full length T. gondii Cdk7, CyclinH and Mat1. TgCdk7: putative cyclin binding domain (CBD: 40–46 aa), ATP binding domain (ABD: 59–64 aa) and T-loop domain (198–281 aa) are shown. TgCyclinH: putative cyclin box (124–208 aa), monopartite nuclear localization signal (244–254 aa) and bipartite nuclear localization signal (505–520 aa) are shown. TgMat1: putative ring finger domain (6–56 aa) is shown. (B) S. cerevisiae strains with chromosomal copy deletion of kin28, ccl1 and tfb3 genes were transformed with yeast expression vector (pYES3/CT) carrying trp selection marker and the coding regions of respective S. cerevisiae wild type genes and T. gondii cdk7, cyclinH and mat1 genes. Transformants were selected for tryptophan prototrophy by growing on medium lacking tryptophan. Selected colonies were streaked on to tryptophan-dropout medium with or without 1 mg/ml FOA. ScKin28, ScCcl1, ScTfb3 along with TgCdk7, TgCyclinH, TgMat1 could rescue the growth of kin28, ccl1, tfb3 mutant yeast strains respectively, in the presence of FOA, whereas empty vector could not support the genetic complementation of the strains under the same experimental conditions. (C) T. gondii genes cdk7, cyclinH and mat1 were expressed in the respective transformants as shown by Western blotting using ant-His antibody. S. cerevisiae GAPDH was used as a loading control (bottom panel).