tailieunhanh - Báo cáo khóa học: FTIR spectroscopy shows structural similarities between photosystems II from cyanobacteria and spinach

Photosystem II (PSII), an essential component of oxygenic photosynthesis, is a membrane-bound pigment protein complex found in green plants and cyanobacteria. Whereas the molecular structure of cyanobacterial PSII has been resolved with at least medium resolution [Zouni, A., Witt, ., Kern, J., Fromme, P., Krauss, N., Saenger, W. & Orth, P. (2001)Nature (London)409, 739–743; Kamiya, N. &Shen, . (2003)Proc. Natl Acad. Sci. USA100, 98–103], the structure of higher plant PSII is only known at low resolution. . | Eur. J. Biochem. 271 563-567 2004 FEBS 2004 doi FTIR spectroscopy shows structural similarities between photosystems II from cyanobacteria and spinach André Remv1. Jens Niklas1 Helena Kuhl2 Petra Kellers1 Thomas Schott2 Matthias Roaner2 and Klaus Gerwert1 1Lehrstuhl fur Biophysik and 2Lehrstuhl fur Biochemie der Pflanzen Ruhr-Universitat Bochum Germany Photosystem II PSII an essential component of oxygenic photosynthesis is a membrane-bound pigment protein complex found in green plants and cyanobacteria. Whereas the molecular structure of cyanobacterial PSII has been resolved with at least medium resolution Zouni A. Witt . Kern J. Fromme P. Krauss N. Saenger W. Orth P. 2001 Nature London 409 739-743 Kamiya N. Shen . 2003 Proc. Natl Acad. Sci. USA 100 98-103 the structure of higher plant PSII is only known at low resolution. Therefore Fourier transform infrared FTIR difference spectroscopy was used to compare PSII from both Thermosynechococcus elongatus and Synechocystis PCC6803 core complexes with PSII-enriched membranes from spinach BBY . FTIR difference spectra of T. elonga-tus core complexes are presented for several different intermediates. As the FTIR difference spectra show close similarities among the three species the structural arrangement of cofactors in PSII and their interactions with the protein microenvironment during photosynthetic charge separation must be very similar in higher plant PSII and cyanobacterial PSII. A structural model of higher plant PSII can therefore be predicted from the structure of cyanobac-terial PSII. Keywords cyanobacteria higher plants photosynthesis photosystem II structure. Photosystem II PSII is a membrane-bound pigment protein complex found in plants algae and cyanobacteria 1 . Light energy is absorbed by light-harvesting complexes and transferred to the primary donor P680 two chlorophyll a molecules. The excitation of P680 leads to electron transfer via a pheophytin HA to the .