Figure 3.

CIB1 Is a DNA Binding Protein Interacting with the E-Box (CANNTG) DNA Sequence.

(A) The alignment of DNA sequences selected by CIB1 via the random binding site selection assay (see Methods). Over 80% sequences selected by CIB1 contain the E-box element (CANNTG) (http://weblogo.berkeley.edu/).

(B) A competitive EMSA showing the interaction of CIB1 with the DIG-labeled E-box DNA. The CIB1–DNA interaction was completed by the unlabeled wild-type E-box (Ewt) or the mutant E-box (Em4) as shown in (C). Black wedges represent increasing amounts of competitors (12.5×, 25×, and 50× in molar excess).

(C) The DNA sequences of the wild-type E-box DNA (Ewt) and mutant E-box sequence (Em) competitors.

(D) A quantitative analysis of the competitive EMSA using the Ewt or Em competitors. Signals of the CIB1-bound probe in the presence of unlabeled oligonucleotide competitor (+UOC) are normalized by that in the absence of the unlabeled oligonucleotide competitor (-UOC) and presented as RBUs.