Localization of two phylloquinones, Q(K) and Q(K)', in an improved electron density map of photosystem I at 4-Å resolution

Olaf Klukas, Wolf Dieter Schubert, Patrick Jordan, Norbert Krauß, Petra Fromme, Horst Tobias Witt, Wolfram Saenger

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An improved electron density map of photosystem I from Synechococcus elongatus calculated at 4-Å resolution for the first time reveals a second phylloquinone molecule and thereby completes the set of cofactors constituting the electron transfer system of this iron-sulfur type photosynthetic reaction center: six chlorophyll a, two phylloquinones, and three Fe4S4 clusters. The location of the newly identified phylloquinone pair, the individual plane orientations of these molecules, and the resulting distances to other cofactors of the electron transfer system are discussed and compared with those determined by magnetic resonance techniques.

Original languageEnglish
Pages (from-to)7361-7367
Number of pages7
JournalJournal of Biological Chemistry
Issue number11
Publication statusPublished - Mar 12 1999


ASJC Scopus subject areas

  • Biochemistry

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