(P2A-1) Mutational analysis of the two phylloquinones in Photosystem I. (Abstract 181)
Feifei Gu^*,1, Martin Byrdin², Fabrice Rappaport², Art van der Est³, Fraser MacMillan⁴, Kevin Redding¹, ¹ University of Alabama, Tuscaloosa, AL, USA² Institut de Biologie Physico-Chimique, Paris, France³ Brock University, Ontario, Canada⁴ J.W. Goethe University, Frankfurt am Main, Germany

(P2A-2) Spectroscopic studies of electron transfer reactions in membranes and isolated reaction center from Heliobacterium modesticaldum. (Abstract 182)
Hirozo Oh-oka^*,1, Masayo Iwaki², Ryo Miyamoto³, Hiroyuki Mino³, Shigeru Itoh³, ¹ Department of Biology, Graduate School of Science, Osaka University, Osaka, Japan² Department of Biology, University College London, London, UK³ Division of Material Science, Graduate School of Science, Nagoya University, Nagoya, Japan

(P2A-3) Temperature dependence of charge recombination in Photosystem I trimers embedded in trehalose glass. (Abstract 183)
Rufat Agalarov^*,1, Ramakrishnan Balasubramanian¹, John Golbeck^{1, 2}, ¹ Department of Biochemistry and Molecular Biology, University Park, PA, USA² Department of Chemistry, Pennsylvania State University, University Park, PA, USA

(P2A-4) Iron sulfur cluster assembly in Photosystem I: The role of the transcriptional repressor SufR in regulating the suf regulon in cyanobacterium Synechococcus sp. PCC 7002. (Abstract 184)
Ramakrishnan Balasubramanian^*,1, Tao Wang¹, Gaozhong Shen¹, Lee Hoffart¹, Carsten Krebs^{1, 2}, Lee McIntosh³, Donald Bryant¹, John Golbeck^{1, 2}, ¹ Department of Biochemistry and Molecular Biology, University Park, PA, United States² Department of Chemistry, University Park, PA, United States³ MSU-DOE Plant Research Laboratory, East Lansing, MI, United States

(P2A-5) Red absorption changes accompanying electron transfer from A₁ to the iron-sulfur clusters in Photosystem I. (Abstract 185)
Krzysztof Dobek^{1, 2}, Klaus Brettel^*,2, ¹ Quantum Electronics Division, Department of Physics, Poznan, Poland² Service de Bioenergetique, Gif-sur-Yvette Cedex, France

(P2A-6) Exploring the rate of forward electron transfer in PSI with a series of anthraquinones in the A₁ binding site. (Abstract 186)
Sarah Brown^*,1, Julia Pushkar², Irina Karygina², Dietmar Stehlik², Art van der Est¹, ¹ Brock University, St. Catharines, Ontario, Canada² Institut für Experimentalphysik, Berlin, Germany

(P2A-7) EPR study on the arrangement of the terminal [4Fe-4S] clusters in the reaction center of green sulfur bacteria. (Abstract 187)
K. Lakshmi^*,1, Wade Johnson², John Golbeck², Gary Brudvig¹, ¹ Department of Chemistry, New Haven, CT, USA² Department of Biochemistry and Molecular Biology, University Park, PA, USA

(P2A-8) Antenna ring around trimeric Photosystem I in a photosynthetic prokaryote Prochlorothrix hollandica. (Abstract 188)
Ladislav Bumba^{*,1, 3}, Ondrej Prasil², Frantisek Vacha^{2, 3}, ¹ Faculty of Biological Sciences, Ceske Budejovice, Czech republic³ Institute of Plant Molecular Biology, Ceske Budejovice, Czech republic² Institute of Physical Biology, Nove Hrady, Czech republic

(P2A-9) Methionine to asparagine mutations of the A_o chlorophyll ligand in the PsaA and PsaB subunits of Photosystem I in Synechocystis sp. PCC 6803. (Abstract 189)
Rachel Cohen^*,1, Wu Xu², Parag Chitnis², John Golbeck¹, ¹ 1 Department of biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA² Department of Biochemistry, Molecular Biology, and Biophysics, Iowa State University, Ames, IA, 50010, USA

(P2A-10) Probing the active electron transfer branch in Photosystem I reaction center from Synechocystis sp. PCC 6803 by means of ultrafast spectroscopy. (Abstract 190)
Naranbaatar Dashdorj^*,1, Wu Xu², John Golbeck³, Parag Chitnis², Sergei Savikhin¹, ¹ Department of Physics, West Lafayette, IN, USA² Department of Biochemistry, Biophysics, and Molecular Biology, Ames, IA, USA³ Department of Biochemistry and Molecular Biology, University Park, PA, USA

(P2A-11) Measurement of electron transfer via both phylloquinones in the Photosystem I reaction centre of Chlamydomonas. (Abstract 191)
Peter Heathcote^*,1, Stefano Santabarbara¹, Ilya Kuprov², Wendy Fairclough¹, Peter Hore², Saul Purton³, Michael Evans³, ¹ School of Biological Sciences, London, UK² Department of Chemistry, Oxford, UK³ Department of Biology, London, UK

(P2A-12) Electron paramagnetic resonance spectra and protein composition of photosynthetic reaction centers from Heliobacterium modesticaldum. (Abstract 192)
Mark Heinnickel^*,1, Gaozhong Shen¹, John Golbeck^{1, 2}, ¹ Department of Biochemistry and Molecular Biology, USA² Department of Chemistry, University Park, PA, USA

(P2A-13) Quantitative molecular volume changes of photoreactions in photosynthesis and visual system revealed by pulsed photoacoustic spectroscopy. (Abstract 193)
Harvey Jian-Min Hou^*,1, Thomas Sakmar², David Mauzerall², ¹ Department of Chemistry, Gonzaga University, Spokane, WA, USA² The Rockefeller University, New York, NY, USA

(P2A-14) Characterization of Photosystem I complex purified from a diatom, Chaetoceros gracilis. (Abstract 194)
Yohei Ikeda^*,1, Kazuhiko Satoh¹, Yasuhiro Kashino¹, ¹ Himeji Institute of Technology, Faculty of Science, Hyogo, 678-1297, Japan

(P2A-15) Purification of two ferredoxins and cloning their genes from the photosynthetic bacterium Heliobacillus mobilis. (Abstract 195)
Atsushi Hatano¹, Daisuke Seo², Masaharu Kitashima^*,1, Hidehiro Sakurai², Kazuhito Inoue¹, ¹ Dept. Biol. Sci., Hiratsuka, Kanagawa, Japan² Dept. Biol., Shinjuku, Tokyo, Japan

(P2A-16) Delicate distinction between absorption spectra of bacteriochlorophyll epimers. (Abstract 196)
Kuniyuki TAKAHASHI¹, Yuka ITOH¹, Machiko AKIYAMA¹, Tadashi WATANABE², Kazuhito INOUE³, Toru OBA⁴, Mitsuo UMETSU⁵, Masami KOBAYASHI^*,1, ¹ Inst. Materials Sci., Univ. Tsukuba, Japan² Inst. Industrial Sci., Univ. Tokyo, Japan³ Dept. Biol. Sci., Kanagawa Univ., Japan⁴ Dept. Appl. Chem., Utsunomiya Univ, Japan⁵ Inst. Multi. Res. Adv. Mat., Tohoku Univ., Japan

(P2A-17) Energy transfer and charge separation dynamics in chlorophyll d-based Photosystem I from Acaryochloris marina. (Abstract 197)
Shigeichi Kumazaki^*,1, Isamu Ikegami², Shigeru Itoh³, ¹ Department of Chemistry, Graduate School of Science, Kyoto, Japan² Faculty of Pharmaceutical Sciences, Sagamiko, Kanagawa, Japan³ Department of Physics, Graduate School of Science, Nagoya, Japan

(P2A-18) Directionality of electron transport through Photosystem I of Chlamydomonas reinhardtii probed by transient electron paramagnetic resonance. (Abstract 198)
Michael McConnell^*,1, V.M. Ramesh¹, Ingelög Wyndhamn², Art van der Est², Andrew Webber¹, ¹ School of Life Sciences and Center for the Study of Early Events in Photosynthesis, Tempe, Arizona, USA² Department of Chemistry, St. Catharines, Ontario, Canada

(P2A-19) Excited state dynamics in the PSI-LHCI supercomplex from Chlamydomonas reinhardtii: excitation wavelength dependence study. (Abstract 199)
Alexander Melkozernov^*,1, Joanna Kargul², Su Lin¹, James Barber², Robert Blankenship¹, ¹ Department of Chemistry and Biochemistry, Tempe, AZ, USA² Wolfson Laboratories, Department of Biological Sciences, London, UK

(P2A-20) Functional characterization of the evolutionarily divergent fern plastocyanin. (Abstract 200)
José Navarro^*,1, Christian Lowe², Reinout Amons³, Takamitsu Kohzuma⁴, Gerard Canters², Miguel de la Rosa¹, Marcellus Ubbink², Manuel Hervás¹, ¹ Instituto de Bioquímica Vegetal y Fotosíntesis, Sevilla, Sevilla, Spain² Leiden Institute of Chemistry, Leiden, The Netherlands³ Department of Molecular Cell Biology, Leiden, The Netherlands⁴ Department of Chemistry, Mito, Japan

(P2A-21) The requirement of carotenoids for the stable assembly of the photosynthetic complexes. (Abstract 201)
Kulsam Ali¹, Michael Evans¹, Saul Purton^*,1, ¹ Department of Biology, London, United Kingdom

(P2A-22) Asymmetric hydrogen bonding between the quinone electron acceptor and the protein in Photosystem I as studied by various EPR methods. (Abstract 202)
Yulia Pushkar^*,1, Herbert Zimmermann², Dietmar Stehlik¹, ¹ Institut für Experimentalphysik, Freie Universität Berlin, Berlin, Germany² Max-Planck Institut für Medizinische Forschung, Jahnstrasse 29, Heidelberg, Germany

(P2A-23) The role of the asymmetric protein environment upon the properties of P₇₀₀. (Abstract 203)
Kevin Redding^*,1, Maria Pantelidou², Tatyana Konovalova¹, Johan van Tol³, Fabrice Rappaport⁴, Gary Hastings⁵, Brian Abbott¹, Alexander Petrenko¹, ¹ The University of Alabama, Tuscaloosa, Alabama, USA² Iowa State University, Ames, Iowa, USA³ National High Magnetic Field Laboratory, Tallahassee, Florida, USA⁴ Institut de Biologie Physico-Chimique, Paris, France⁵ Georgia State University, Atlanta, GA, USA

(P2A-24) Photochemically induced dynamic nuclear polarization in Photosystem I observed by ¹³C magic-angle spinning NMR. (Abstract 204)
Esha Roy^*,1, Alia¹, Peter Gast², Hans van Gorkom², Huub de Groot¹, Gunnar Jeschke³, Jörg Matysik¹, ¹ Leiden Institute of Chemistry, Leiden, The Netherlands² Department of Biophysics, Leiden, The Netherlands³ Max-Planck-Institut für Polymerforschung, Mainz, Germany

(P2A-25) A new model for electron transfer in PSI: equilibrium between F_X and both phylloquinones. (Abstract 205)
Stefano Santabarbara^*,1, Peter Heathcote¹, Micheal Evans², ¹ School of Biological Sciences, Queen Mary University of London, London, United Kingdom² Department of Biology, University College London, United kingdom

(P2A-26) Spectral properties of the PS I reaction center from T. elongatus: structure-based modelling of optical spectra. (Abstract 206)
Eberhard Schlodder^*,1, Enrica Bordignon², Thomas Renger³, ¹ Max-Volmer-Laboratorium für Biophysikalische Chemie, Berlin, Germany² Universität Osnabrück, Osnabrück, Germany³ Institut für Chemie (Kristallographie), Berlin, Germany

(P2A-27) Functional genomics of genes for biogenesis of Fe/S proteins in cyanobacteria. (Abstract 207)
Gaozhong Shen^*,1, Ramakrishnan Balasubramanian¹, Tao Wang¹, Bhramara Tirupati¹, Martin Bollinger^{1, 2}, John Golbeck^{1, 2}, Donald Bryant¹, ¹ Department of Biochemistry & Molecular Biology, University Park, PA, USA² Department of Chemistry, University Park, PA, USA

(P2A-28) The energy gap between P₇₀₀⁺-A₀^- and P₇₀₀^* in Photosystem I determined by delayed fluorescence at 270-77 K. (Abstract 208)
Yutaka Shibata^*,1, Takashi Kasahara¹, Sinpei Akai¹, Shigeru Itoh¹, Isamu Ikegami², ¹ School of Material Science (Physics), Nagoya, Japan² Teikyo University, School of Pharmaceutical Sciences, Tsukui-gun, Kanagawa, Japan

(P2A-29) Structural analysis of PSI-LHC supercomplexes of state I and state I forms from Chlamydomonas reinhardtii. (Abstract 209)
Rajagopal Subramanyam^{*,1, 3}, Ingo Grotjohann^{2, 3}, Jean-David Rochaix⁴, Petra Fromme^{2, 3}, Andrew Webber^{1, 3}, ¹ School of Life Sciences, Arizona State University, Tempe, Arizona, USA³ Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona, USA² Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, USA⁴ Departments of Molecular Biology and Plant Biology, University of Geneva,12111 Geneva 4, Switzerland

(P2A-30) Excitation-energy trapping to P₇₀₀ from core-antenna pigments including red Chls in Photosystem I. (Abstract 210)
Hitoshi SUMI^*,, Koichiro MUKAI¹, ¹ Institute of Materials Science, Tsukuba, Ibaraki-ken, Japan

(P2A-31) The unique properties of Photosystem I of a cyanobacterium Gloeobacter violaceus PCC7421. (Abstract 211)
Hidetoshi Inoue¹, Tohru Tsuchiya^{*,1, 2}, Soichirou Stoh³, Hideaki Miyashita^{1, 2}, Ayumi Tanaka³, Mamoru Mimuro^{1, 2}, ¹ Graduate School of Human and Environmental Studies, Japan² Department of Technology and Ecology, Japan³ The Institute of Low Temperature Science, Japan

(P2A-32) The function of the PscD subunit of the photosynthetic reaction center complex in Chlorobium tepidum. (Abstract 212)
Yusuke Tsukatani^*,1, Shigeru Itoh², Ryo Miyamoto², Hirozo Oh-oka¹, ¹ Department of Biology, Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan² School of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan

(P2A-33) Alteration of phenylalanine F669(PsaB) slows electron transfer in the PsaA branch of Photosystem I. (Abstract 213)
Art van der Est^*,1, Yuri Kandrashkin¹, John Golbeck², ¹ Dept. of Chemistry, Brock University, St Catharines, Ontario, Canada² Dept. of Biochemistry and Molecular Biology, University Park, PA, USA

(P2A-34) Evidence for bi-directional electron transfer in Chlamydomonas PSI: analysis of mutants of the axial ligands to Chl A₀. (Abstract 214)
Velupillai Mani Ramesh^*,1, Krzysztof Gibasiewicz, Su Lin, Scott Bingham¹, Andrew Webber¹, ¹ School of Life Sciences,Center for the Study of Early Events in Photosynthesis, Tempe, AZ, USA

(P2A-35) Computed infrared spectra of protonated and metal-bound methylimidazole. (Abstract 215)
Ruili Wang^*,1, Gary Hastings^*,1, ¹ Department of Physics and Astronomy, Atlanta, GA, USA

(P2A-36) Electron transfer along both branches of excitonically coupled chlorophylls in PSI. (Abstract 216)
Andrew Webber^*,1, V Ramesh¹, Krzysztof Gibasiewicz³, Su Lin¹, Neal Woodbury¹, ¹ School of Life Sciences, Tempe, AZ, USA³ Department of Physics, Poland

(P2A-37) Photosynthetic electron transport supported by methyl viologen in the obligate shade plants Panax ginseng and Panax quinquefolius. (Abstract 217)
Matthew Woods^*,1, Graeme Parmenter², Julie-Ann Miskell¹, Julian Eaton-Rye¹, ¹ Biochemistry Department, Dunedin, New Zealand² New Zealand Institute for Crop and Food Research Ltd, Mosgeil, New Zealand.

(P2A-38) Low-temperature electron transfer in A₀ binding site point mutants studied using transient EPR and CW-EPR. (Abstract 218)
Ingelög Wyndhamn^*,1, Art van der Est¹, Rachel Cohen², John Golbeck², ¹ Department of Chemistry, Brock University, 500 Glenridge Avenue, St.Catharines, ON, CANADA²