Low temperature EPR on photosystem I single crystals: Orientation of the iron-sulfur centers F(A) and F(B)

Andreas Kamlowski, Arthur Van Der Est, Petra Fromme, Dietmar Stehlik

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Low temperature EPR results from Photosystem I (PS I) single crystals of Synechococcus elongatus are presented. Illumination at 150 K and pH 6.4 is used to photoreduce the two terminal 4Fe-4S centers to the noninteracting state (F(A)-) + (F(B)-). From the EPR data and the analysis of the rotation pattern for both F(A)- and F(B)- the following information is obtained: (i) the principal values of the g tensors of F(A)- and F(B)-, (ii) the orientations of their principal g tensor axes with respect to the crystal axes for each of the six PS I centers per unit cell, and (iii) their orientation with respect to one another. In addition, significant differences between F(A)- and F(B)- are noted with respect to the orientational dependence of the linewidth and the saturation behavior of their EPR signals. In principle, six relative arrangements of the g tensors of F(A)- and F(B)- are consistent with the EPR data. Only two out of these six are compatible with the known structure of the bacterial fenedoxin from P. aerogenes (PaFd) (Adman, E.T., Siecker, L.C, and Jensen, L.H. (1976) J. Biol. Chem. 251, 3801) which has been used as a model for the core of the PsaC protein carrying F(A) and F(B) in PS I. It is concluded that the PaFd and the PsaC protein are analogous with respect to the central part of their structures. The results and conclusions are compared to those obtained from studies on oriented membranes.

Original languageEnglish
Pages (from-to)185-198
Number of pages14
JournalBiochimica et Biophysica Acta - Bioenergetics
Volume1319
Issue number2-3
DOIs
Publication statusPublished - Apr 11 1997

Fingerprint

Photosystem I Protein Complex
Sulfur
Crystal orientation
Paramagnetic resonance
Iron
Single crystals
Synechococcus
Tensors
Bacterial Structures
Temperature
Lighting
Membranes
Linewidth
Crystals
psaB subunit photosystem I

Keywords

  • EPR
  • F(A)
  • F(B)
  • Iron-sulfur center
  • Low temperature EPR
  • Photoreduction
  • Photosystem I crystal

ASJC Scopus subject areas

  • Biophysics

Cite this

Low temperature EPR on photosystem I single crystals : Orientation of the iron-sulfur centers F(A) and F(B). / Kamlowski, Andreas; Van Der Est, Arthur; Fromme, Petra; Stehlik, Dietmar.

In: Biochimica et Biophysica Acta - Bioenergetics, Vol. 1319, No. 2-3, 11.04.1997, p. 185-198.

Research output: Contribution to journalArticle

@article{157349d20212453e939466db3ae40c23,
title = "Low temperature EPR on photosystem I single crystals: Orientation of the iron-sulfur centers F(A) and F(B)",
abstract = "Low temperature EPR results from Photosystem I (PS I) single crystals of Synechococcus elongatus are presented. Illumination at 150 K and pH 6.4 is used to photoreduce the two terminal 4Fe-4S centers to the noninteracting state (F(A)-) + (F(B)-). From the EPR data and the analysis of the rotation pattern for both F(A)- and F(B)- the following information is obtained: (i) the principal values of the g tensors of F(A)- and F(B)-, (ii) the orientations of their principal g tensor axes with respect to the crystal axes for each of the six PS I centers per unit cell, and (iii) their orientation with respect to one another. In addition, significant differences between F(A)- and F(B)- are noted with respect to the orientational dependence of the linewidth and the saturation behavior of their EPR signals. In principle, six relative arrangements of the g tensors of F(A)- and F(B)- are consistent with the EPR data. Only two out of these six are compatible with the known structure of the bacterial fenedoxin from P. aerogenes (PaFd) (Adman, E.T., Siecker, L.C, and Jensen, L.H. (1976) J. Biol. Chem. 251, 3801) which has been used as a model for the core of the PsaC protein carrying F(A) and F(B) in PS I. It is concluded that the PaFd and the PsaC protein are analogous with respect to the central part of their structures. The results and conclusions are compared to those obtained from studies on oriented membranes.",
keywords = "EPR, F(A), F(B), Iron-sulfur center, Low temperature EPR, Photoreduction, Photosystem I crystal",
author = "Andreas Kamlowski and {Van Der Est}, Arthur and Petra Fromme and Dietmar Stehlik",
year = "1997",
month = "4",
day = "11",
doi = "10.1016/S0005-2728(96)00161-2",
language = "English",
volume = "1319",
pages = "185--198",
journal = "Biochimica et Biophysica Acta - Bioenergetics",
issn = "0005-2728",
publisher = "Elsevier",
number = "2-3",

}

TY - JOUR

T1 - Low temperature EPR on photosystem I single crystals

T2 - Orientation of the iron-sulfur centers F(A) and F(B)

AU - Kamlowski, Andreas

AU - Van Der Est, Arthur

AU - Fromme, Petra

AU - Stehlik, Dietmar

PY - 1997/4/11

Y1 - 1997/4/11

N2 - Low temperature EPR results from Photosystem I (PS I) single crystals of Synechococcus elongatus are presented. Illumination at 150 K and pH 6.4 is used to photoreduce the two terminal 4Fe-4S centers to the noninteracting state (F(A)-) + (F(B)-). From the EPR data and the analysis of the rotation pattern for both F(A)- and F(B)- the following information is obtained: (i) the principal values of the g tensors of F(A)- and F(B)-, (ii) the orientations of their principal g tensor axes with respect to the crystal axes for each of the six PS I centers per unit cell, and (iii) their orientation with respect to one another. In addition, significant differences between F(A)- and F(B)- are noted with respect to the orientational dependence of the linewidth and the saturation behavior of their EPR signals. In principle, six relative arrangements of the g tensors of F(A)- and F(B)- are consistent with the EPR data. Only two out of these six are compatible with the known structure of the bacterial fenedoxin from P. aerogenes (PaFd) (Adman, E.T., Siecker, L.C, and Jensen, L.H. (1976) J. Biol. Chem. 251, 3801) which has been used as a model for the core of the PsaC protein carrying F(A) and F(B) in PS I. It is concluded that the PaFd and the PsaC protein are analogous with respect to the central part of their structures. The results and conclusions are compared to those obtained from studies on oriented membranes.

AB - Low temperature EPR results from Photosystem I (PS I) single crystals of Synechococcus elongatus are presented. Illumination at 150 K and pH 6.4 is used to photoreduce the two terminal 4Fe-4S centers to the noninteracting state (F(A)-) + (F(B)-). From the EPR data and the analysis of the rotation pattern for both F(A)- and F(B)- the following information is obtained: (i) the principal values of the g tensors of F(A)- and F(B)-, (ii) the orientations of their principal g tensor axes with respect to the crystal axes for each of the six PS I centers per unit cell, and (iii) their orientation with respect to one another. In addition, significant differences between F(A)- and F(B)- are noted with respect to the orientational dependence of the linewidth and the saturation behavior of their EPR signals. In principle, six relative arrangements of the g tensors of F(A)- and F(B)- are consistent with the EPR data. Only two out of these six are compatible with the known structure of the bacterial fenedoxin from P. aerogenes (PaFd) (Adman, E.T., Siecker, L.C, and Jensen, L.H. (1976) J. Biol. Chem. 251, 3801) which has been used as a model for the core of the PsaC protein carrying F(A) and F(B) in PS I. It is concluded that the PaFd and the PsaC protein are analogous with respect to the central part of their structures. The results and conclusions are compared to those obtained from studies on oriented membranes.

KW - EPR

KW - F(A)

KW - F(B)

KW - Iron-sulfur center

KW - Low temperature EPR

KW - Photoreduction

KW - Photosystem I crystal

UR - http://www.scopus.com/inward/record.url?scp=0030980887&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030980887&partnerID=8YFLogxK

U2 - 10.1016/S0005-2728(96)00161-2

DO - 10.1016/S0005-2728(96)00161-2

M3 - Article

AN - SCOPUS:0030980887

VL - 1319

SP - 185

EP - 198

JO - Biochimica et Biophysica Acta - Bioenergetics

JF - Biochimica et Biophysica Acta - Bioenergetics

SN - 0005-2728

IS - 2-3

ER -