Evolutionary variation of the CCAAT-binding transcription factor NF-Y

NF-Y is a CCAAT-speclfic transcription factor thought to be involved in the regulation of a variety of eukaryotic genes. It shows a striking sequence similarity with the yeast factor HAP2/3. In an attempt to trace back its evolutionary history, we succeeded in Isolating NF-Y cDNA clones from a plant and from several species of vertebrates. The patterns of sequence conservation delineate potential functional domains: A central, highly conserved, domain likely responsible for DNA-binding and subunlt interaction; more evolutionatily flexible flanking regions, In which variability is clustered, individualizing conserved glutamine or acidic amino-acids putatively involved in protein-protein contacts.