The FMO protein is related to PscA in the reaction center of green sulfur bacteria

John M. Olson, Jason Raymond

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


The Fenna-Matthews-Olson protein is a water-soluble protein found only in green sulfur bacteria. Each subunit contains seven bacteriochlorophyll (BChl) a molecules wrapped in a string bag of protein consisting of mostly β sheet. Most other chlorophyll-binding proteins are water-insoluble proteins containing membrane-spanning α helices. We compared an FMO consensus sequence to well-characterized, membrane-bound chlorophyll-binding proteins: L & M (reaction center proteins of proteobacteria), D1 & D2 (reaction center proteins of PS II), CP43 & CP47 (core proteins of PS II), PsaA & PsaB (reaction center proteins of PS I), PscA (reaction center protein of green sulfur bacteria), and PshA (reaction center protein of heliobacteria). We aligned the FMO sequence with the other sequences using the PAM250 matrix modified for His binding-site identities and found a signature sequence (LxHHxxxGxFxxF) common to FMO and PscA. (The two His residues are BCh1 a. binding sites in FMO.) This signature sequence is part of a 220-residue C-terminal segment with an identity score of 13%. PRSS (Probability of Random Shuffle) analysis showed that the 220-residue alignment is better than 96% of randomized alignments. This evidence supports the hypothesis that FMO protein is related to PscA.

Original languageEnglish (US)
Pages (from-to)277-285
Number of pages9
JournalPhotosynthesis research
Issue number3
StatePublished - 2003


  • FMO protein
  • Green sulfur bacteria
  • PscA
  • Reaction center

ASJC Scopus subject areas

  • Biochemistry
  • Plant Science
  • Cell Biology


Dive into the research topics of 'The FMO protein is related to PscA in the reaction center of green sulfur bacteria'. Together they form a unique fingerprint.

Cite this