Abstract
Aureochromes in stramenopiles contain a basic leucine zipper (bZIP) domain in the central region and a light-oxygen-voltage-sensing (LOV) domain, and are thought to function as light-regulated transcription factors. To understand the molecular mechanism, we investigated the photoreactions, oligomeric structures, and DNA binding of recombinant aureochrome-1 (AUREO1). The results suggest that monomeric AUREO1 is present in reduced conditions and undergoes dimerization upon illumination. Blue light-induced dimerization enhances the affinity for the target sequence. Our N-terminally truncated mutants may be useful molecular tools as a photoactivatable-bZIP module (Photozipper) for optogenetics and biophysical analyses.
