Protein-cofactor interactions in bioenergetic complexes: The role of the A1A and A1B phylloquinones in Photosystem I

Nithya Srinivasan, John H. Golbeck

Research output: Contribution to journalReview articlepeer-review

98 Scopus citations


This review focuses on phylloquinone as an indispensable link between light-induced charge separation and subsequent charge stabilization in Photosystem I (PS I). Here, the role of the polypeptide in conferring the necessary kinetic and thermodynamic properties to phylloquinone so as to specify its functional role in PS I electron transfer is discussed. Photosynthetic electron transfer and the role of quinones in Type I and Type II reaction centers are introduced at the outset with particular emphasis on the determination of redox potentials of the cofactors. Currently used methodologies, particularly time-resolved optical spectroscopy and varieties of magnetic resonance spectroscopy that have become invaluable in uncovering the details of phylloquinone function are described in depth. Recent studies on the selective alteration of the protein environment and on the incorporation of foreign quinones either by chemical or genetic means are explored to assess how these studies have improved our understanding of protein-quinone interactions. Particular attention is paid to the function of the H-bond, methyl group and phytyl tail of the phylloquinone in interacting with the protein environment.

Original languageEnglish (US)
Pages (from-to)1057-1088
Number of pages32
JournalBiochimica et Biophysica Acta - Bioenergetics
Issue number9
StatePublished - Sep 2009

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Biochemistry
  • Cell Biology

Fingerprint Dive into the research topics of 'Protein-cofactor interactions in bioenergetic complexes: The role of the A<sub>1A</sub> and A<sub>1B</sub> phylloquinones in Photosystem I'. Together they form a unique fingerprint.

Cite this