Dinucleotide fold proteins. Interaction of arabinose binding protein with Cibacron Blue 3G-A.

Cibacron Blue 3G-A, the dye moiety of Blue dextran-Sepharose, has been shown to not specifically bind a protein with a dinucleotide fold-like supersecondary structure, L-arabinose binding protein from Escherichia coli. This shows that Cibacron Blue 3G-A is not suitable as a definitive probe for the dinucleotide fold as suggested earlier (Thompson et al., 1975; Stellwagen, 1977). An explanation for the large predominance of proteins containing this protein supersecondary structure that bind to this dye is presented.