2pd8

Publication Abstract from PubMed

The Neurospora crassa photoreceptor Vivid tunes blue-light responses and modulates gating of the circadian clock. Crystal structures of dark-state and light-state Vivid reveal a light, oxygen, or voltage Per-Arnt-Sim domain with an unusual N-terminal cap region and a loop insertion that accommodates the flavin cofactor. Photoinduced formation of a cystein-flavin adduct drives flavin protonation to induce an N-terminal conformational change. A cysteine-to-serine substitution remote from the flavin adenine dinucleotide binding site decouples conformational switching from the flavin photocycle and prevents Vivid from sending signals in Neurospora. Key elements of this activation mechanism are conserved by other photosensors such as White Collar-1, ZEITLUPE, ENVOY, and flavin-binding, kelch repeat, F-BOX 1 (FKF1).

Conformational switching in the fungal light sensor Vivid.,Zoltowski BD, Schwerdtfeger C, Widom J, Loros JJ, Bilwes AM, Dunlap JC, Crane BR Science. 2007 May 18;316(5827):1054-7. PMID:17510367^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.