Photosynthesis Research

, Volume 86, Issue 1–2, pp 175–184

The Antenna System of Photosystem II From Thermosynechococcus elongatus at 3.2 Å Resolution

  • Bernhard Loll
  • Jan Kern
  • Athina Zouni
  • Wolfram Saenger
  • Jacek Biesiadka
  • Klaus-Dieter Irrgang
Regular Paper

DOI: 10.1007/s11120-005-4117-0

Cite this article as:
Loll, B., Kern, J., Zouni, A. et al. Photosynth Res (2005) 86: 175. doi:10.1007/s11120-005-4117-0

Abstract

The content and type of cofactors harboured in the Photosystem II core complex (PS IIcc) of the cyanobacterium Thermosynechococcus elongatus has been determined by biochemical and spectroscopic methods. 17 ± 1 chlorophyll a per pheophytin a and 0.25 β-carotene per chlorophyll a have been found in re-dissolved crystals of dimeric PS IIcc. The X-ray crystal structure of PS IIcc from Thermosynechococcus elongatus at 3.2 Å resolution clearly shows chlorophyll a molecules arranged in two layers close to the cytoplasmic and lumenal sides of the thylakoid membrane. Each of the cytoplasmic layers contains 9 chlorophyll a, whose positions and orientations are related by a local twofold rotation pseudo-C2 axis passing through the non-haem Fe2+. These chlorophyll a are arranged comparably to those in the antenna domains of PsaA and PsaB of cyanobacterial Photosystem I affirming an evolutionary relation. The chlorophyll a in the lumenal layer are less well conserved between Photosystems I and II and even between CP43 and CP47 with 4 chlorophyll a in the former and 7 in the latter.

Keywords

antenna system crystal structure excitation energy transfer Photosystem II Thermosynechococcus elongatus the antenna system of Photosystem II 

Abbreviations

Car

β-carotene

cc

core complex

Chla

Chlorophyll a

cyt

cytochrome

ETC

electron transfer chain

LHC

light harvesting complex

Pheoa

Pheophytin a

PS

Photosystem

QA

primary quinone

QB

secondary quinone

RPC

reversed phase chromatography

T. elongatus

Thermosynechococcus elongatus

TMH

transmembrane α-helix

Copyright information

© Springer 2005

Authors and Affiliations

  • Bernhard Loll
    • 1
  • Jan Kern
    • 2
  • Athina Zouni
    • 2
  • Wolfram Saenger
    • 1
  • Jacek Biesiadka
    • 1
  • Klaus-Dieter Irrgang
    • 2
  1. 1.Institute of Chemistry/CrystallographyFree University BerlinBerlinGermany
  2. 2.Max-Volmer-Laboratories for Biophysical ChemistryTechnical University BerlinBerlinGermany

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