Identification of a hydrogen bond in the Phe M197→Tyr mutant reaction center of the photosynthetic purple bacteriumRhodobacter sphaeroidesby X-ray crystallography and FTIR spectroscopy1

Andreas Kuglstatter, Petra Hellwig, Günter Fritzsch, Josef Wachtveitl, Dieter Oesterhelt, Werner Mäntele, Hartmut Michel
1999 FEBS Letters  
In bacterial reaction centers the charge separation process across the photosynthetic membrane is predominantly driven by the excited state of the bacteriochlorophyll dimer (D). An X-ray structure analysis of the Phe M197C CTyr mutant reaction center from Rhodobacter sphaeroides at 2.7 A î resolution suggests the formation of a hydrogen bond as postulated by Wachtveitl et al. [Biochemistry 32, 12875^12886, 1993] between the Tyr M197 hydroxy group and one of the 2a-acetyl carbonyls of D. In
more » ... nation with electrochemically induced FTIR difference spectra showing a split band of the Z Z-conjugated 9keto carbonyl of D, there is clear evidence for the existence of such a hydrogen bond.
doi:10.1016/s0014-5793(99)01614-2 pmid:10601661 fatcat:i4litn57onetzca5yi3p6utcpi