Hydrogen bond switching among flavin and amino acid side chains in the BLUF photoreceptor observed by ultrafast infrared spectroscopy.

ABSTRACT: BLUF domains constitute a recently discovered class of photoreceptor proteins found in bacteria and eukaryotic algae. BLUF domains are blue-light sensitive through a FAD cofactor that is involved in an extensive hydrogen-bond network with nearby amino acid side chains, including a highly conserved tyrosine and glutamine. The participation of particular amino acid side chains in the ultrafast hydrogen-bond switching reaction with FAD that underlies photoactivation of BLUF domains is assessed by means of ultrafast infrared spectroscopy. Blue-light absorption by FAD results in formation of FAD(*-) and a bleach of the tyrosine ring vibrational mode on a picosecond timescale, showing that electron transfer from tyrosine to FAD constitutes the primary photochemistry. This interpretation is suppo

SUBMITTER: Bonetti C 

PROVIDER: S-EPMC2576356 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature