Role of NAD binding and catalytic residues in the C-terminal binding protein corepressor
Abstract
CtBP corepressor proteins potentiate the activity of many metazoan transcriptional repressors. These proteins are homologous to prokaryotic D-2-hydroxyacid dehydrogenases, possessing an NAD/NADH binding fold and conserved active site residues. When expressed in Drosophila, a catalytic site mutant retains biological activity, however, we find that an NAD binding mutant lacks biological activity. The NAD mutant, similar to a dimerization mutant, is expressed at low levels, indicating that binding of NAD/NADH may affect CtBP stability. These data support the idea that the ancestral dehydrogenase activity is not required for CtBP function, and NAD binding may play a regulatory, rather than catalytic, role.
Keywords: Corepressor, C-terminal binding protein, CtBP, Transcriptional repression
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PII: S0014-5793(07)01068-X
doi:10.1016/j.febslet.2007.10.011
© 2007 Federation of European Biochemical Societies
