[C-terminal domain of saccharomyces cerevisiae protein ChI4 binds to centromere DNA fragment of yeast chromosome III].

We have expressed in Escherichia coli a recombinant protein consisting of N-terminal peptide omega 10s10 (11 aa) fused with part (aa 135-458) of yeast protein Chl4 involved in the chromosome segregation in Saccharomyces cerevisiae. Mice were immunized with the antigen purified from inclusion bodies, and a polyclonal serum against yeast protein Chl4 was raised. MW of the detected yeast protein Chl4 was approximately 54 kDa, corresponding to the full length ORF translation. C-terminal portion of Chl4 (aa 376-458), containing Helin-Turn-Helix (HTH) motif of DNA-binding, was fused in frame after E. coli maltose binding protein MalE. The soluble fusion was affinity purified using an alternative procedure on the preswollen amylose column. This protein and a 32P labelled 620 bp fragment of yeast CEN3 DNA were used in the DNA-mobility shift assay in polyacrylamide and agarose gels. The binding was detected in the presence and absence of Zn2+ ions. The data obtained could support participation of Chl4 in a direct binding to the yeast centromere in the CBF complex. The result is in a certain agreement with the data on photocrosslinking proteins of the CBF3 complex with the centromere DNA, where the minor protein with a molecular weight of 55-55 kDa was also detected (Espelin C. W. et al., 1997. J. Cell Biol. 139: 1383-1396).