Structure of a novel photoreceptor, the BLUF domain of AppA from Rhodobacter sphaeroides

Spencer Anderson*, Vladimira Dragnea, Shinji Masuda, Joel Ybe, Keith Moffat, Carl Bauer

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    182 Scopus citations

    Abstract

    The flavin-binding BLUF domain of AppA represents a new class of blue light photoreceptors that are present in a number of bacterial and algal species. The dark state X-ray structure of this domain was determined at 2.3 Å resolution. The domain demonstrates a new function for the common ferredoxin-like fold; two long α-helices flank the flavin, which is bound with its isoalloxazine ring perpendicular to a five-stranded β-sheet. The hydrogen bond network and the overall protein topology of the BLUF domain (but not its sequence) bear some resemblance to LOV domains, a subset of PAS domains widely involved in signaling. Nearly all residues conserved in BLUF domains surround the flavin chromophore, many of which are involved in an intricate hydrogen bond network. Photoactivation may induce a rearrangement in this network via reorientation of the Gln63 side chain to form a new hydrogen bond to the flavin O4 position. This shift would also break a hydrogen bond to the Trp104 side chain, which may be critical in induction of global structural change in AppA.

    Original languageEnglish (US)
    Pages (from-to)7998-8005
    Number of pages8
    JournalBiochemistry
    Volume44
    Issue number22
    DOIs
    StatePublished - Jun 7 2005

    ASJC Scopus subject areas

    • Biochemistry

    Fingerprint

    Dive into the research topics of 'Structure of a novel photoreceptor, the BLUF domain of AppA from Rhodobacter sphaeroides'. Together they form a unique fingerprint.

    Cite this