Fig. 1

a Domain structure of the dCTCF protein. b Sephacryl S200 size-exclusion chromatography of dCTCF terminal domains. (N-terminal domain is thioredoxin-tagged.) Positions of molecular weight markers are shown. c Cross-linking of dCTCF N-terminal thioredoxin-tagged deletion derivatives using increasing concentrations of glutaraldehyde (GA). Proteins were separated in a 5–12 % gradient SDS-PAGE gels and visualized with silver-staining. d Summary of the results from chemical cross-linking mapping experiments and limited proteolysis of the dCTCF–NTD multimerization domain. For further experiments see Additional file 2: Figure S2. e Superdex 200 size-exclusion chromatography of dCTCF 1–163 amino acids without thioredoxin. f Analysis of dCTCF protein N-terminal dimerization using yeast two-hybrid assay. Relative N- or C- terminal position of AD/BD is shown. AD GAL4 activation domain, BD GAL4 DNA binding domain