Signal transduction in the photoactive yellow protein. I. Photon absorption and the isomerization of the chromophore.
Molecular dynamics simulation techniques together with time-dependent density functional theory calculations have been used to investigate the effect of photon absorption by a 4-hydroxy-cinnamic acid chromophore on the structural properties of the photoactive yellow protein (PYP) from Ectothiorodospira halophila. The calculations suggest that the protein not only modifies the absorption spectrum of the chromophore but also regulates the subsequent isomerization of the chromophore by stabilizing the isomerization transition state. Although signaling from PYP is thought to involve partial unfolding of the protein, the mechanical effects accompanying isomerization do not appear to directly destabilize the protein.
Groenhof
Gerrit
G
Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, Rijksuniversiteit Groningen, Groningen, The Netherlands.
Lensink
Marc F
MF
Berendsen
Herman J C
HJ
Snijders
Jaap G
JG
Mark
Alan E
AE
D001426:Bacterial Proteins / Q000737:chemistry*; D003198:Computer Simulation; D003373:Coumaric Acids / Q000737:chemistry*; D007536:Isomerism; D007700:Kinetics; D008958:Models, Molecular; D017785:Photons; D020283:Photoreceptors, Microbial / Q000737:chemistry*; D011422:Propionates; D015398:Signal Transduction
D001426:Bacterial Proteins; D003373:Coumaric Acids; D020283:Photoreceptors, Microbial; D011422:Propionates; C050162:photoactive yellow protein, Bacteria; C495469:p-coumaric acid