DICT is a sensory domain found associated with GGDEF, EAL, HD-GYP, STAS, and two component systems (histidine-kinase type). It assumes an alpha+beta fold with a 4-stranded beta-sheet and might have a role in light response (Natural history of sensor domains in bacterial signaling systems by Aravind L, LM Iyer, Anantharaman V, from 'Sensory Mechanisms in Bacteria: Molecular Aspects of Signal Recognition.' Caister Academic Press. 2010) - see (http://de.scribd.com/doc/28576661/Bacterial-Signaling-Chapter)