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Signal transduction in the photoactive yellow protein. II. Proton transfer initiates conformational changes
Author(s) -
Groenhof Gerrit,
Lensink Marc F.,
Berendsen Herman J. C.,
Mark Alan E.
Publication year - 2002
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.10135
Subject(s) - photoisomerization , chromophore , isomerization , chemistry , photochemistry , molecular dynamics , proton , conformational change , biophysics , stereochemistry , computational chemistry , biochemistry , catalysis , biology , physics , quantum mechanics
Molecular dynamics simulation techniques, together with semiempirical PM3 calculations, have been used to investigate the effect of photoisomerization of the 4‐hydroxy‐cinnamic acid chromophore on the structural properties of the photoactive yellow protein (PYP) from Ectothiorodospira halophila . In this bacteria, exposure to blue light leads to a negative photoactic response. The calculations suggest that the isomerization does not directly destabilize the protein. However, because of the isomerization, a proton transfer from a glutamic acid residue (Glu 46 ) to the phenolate oxygen atom of the chromophore becomes energetically favorable. The proton transfer initiates conformational changes within the protein, which are in turn believed to lead to signaling. Proteins 2002;48:212–219. © 2002 Wiley‐Liss, Inc.