Linked Life Data

12779327

Source:http://linkedlifedata.com/resource/pubmed/id/12779327

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
2003-6-3
pubmed:abstractText
The flavoprotein AppA is a blue-light photoreceptor that functions as an antirepressor of photosynthesis gene expression in the purple bacterium Rhodobacter sphaeroides. Heterologous expression studies show that FAD binds to a 156 amino acid N-terminal domain of AppA and that this domain is itself photoactive. A pulse of white light causes FAD absorption to be red shifted in a biphasic process with a fast phase occurring in <1 micros and a slow phase occurring at approximately 5 ms. The absorbance shift was spontaneously restored over a 30 min period, also in a biphasic process as assayed by fluorescence quenching and electronic absorption analyses. Site-directed replacement of Tyr21 with Leu or Phe abolished the photochemical reaction implicating involvement of Tyr21 in the photocycle. Nuclear magnetic resonance analysis of wild-type and mutant proteins also indicates that Tyr21 forms pi-pi stacking interactions with the isoalloxazine ring of FAD. We propose that photochemical excitation of the flavin results in strengthening of a hydrogen bond between the flavin and Tyr 21 leading to a stable local conformational change in AppA.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6726-34
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:12779327-Amino Acid Sequence, pubmed-meshheading:12779327-Bacterial Proteins, pubmed-meshheading:12779327-Circular Dichroism, pubmed-meshheading:12779327-Flavin-Adenine Dinucleotide, pubmed-meshheading:12779327-Flavoproteins, pubmed-meshheading:12779327-Fluorescence, pubmed-meshheading:12779327-Magnetic Resonance Spectroscopy, pubmed-meshheading:12779327-Molecular Sequence Data, pubmed-meshheading:12779327-Mutagenesis, Site-Directed, pubmed-meshheading:12779327-Photochemistry, pubmed-meshheading:12779327-Photolysis, pubmed-meshheading:12779327-Protein Binding, pubmed-meshheading:12779327-Protein Structure, Tertiary, pubmed-meshheading:12779327-Sequence Alignment, pubmed-meshheading:12779327-Sequence Homology, Amino Acid, pubmed-meshheading:12779327-Spectrophotometry, Ultraviolet, pubmed-meshheading:12779327-Tyrosine
pubmed:year
2003
pubmed:articleTitle
Spectroscopic and mutational analysis of the blue-light photoreceptor AppA: a novel photocycle involving flavin stacking with an aromatic amino acid.
pubmed:affiliation
Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't