FIG. 6.
Effects of point mutations in NRREenhII on its affinity for HNF4α. (A) Sequences of NRREenhII and the point mutations introduced into it. The imperfect direct repeats of the NR half-site sequence are boxed. The base pair changes introduced by mutagenesis are underlined and in lowercase. Both are missense mutations in the overlapping X ORF. The amino acid changes are shown beneath the nucleotide sequences. (B) Competition EMSAs to determine the relative affinities of HNF4α for binding wild-type and mutant NRREs. Radiolabeled oligonucleotides containing the wild-type NRREpreC sequence were used as probes, and unlabeled double-stranded oligonucleotides containing the indicated wild-type and mutant NRREs were used as the competitors. Arrows, positions of the DNA-protein complexes and free DNA probe.