On the Mechanism of Activation of the BLUF Domain of AppA

Abstract
AppA, a transcriptional antirepressor, regulates the steady expression of photosynthesis genes in Rhodobacter sphaeroides in response to high-intensity blue light and to redox signals. Its blue-light sensing is mediated by an N-terminal BLUF domain, a member of a novel flavin fold. The photocycle of this domain (App