Abstract
The gene for a reaction center core polypeptide from the anoxygenic photosynthetic bacterium Heliobacillus mobilis was cloned and sequenced. The deduced amino acid sequence consists of 609 residues with a molecular mass of 68 kDa. An adjacent open reading frame is not transcribed under our experimental conditions. No evidence for a second related reaction center core gene was found. The primary sequence of the reaction center protein (P800 protein) shows a high percentage of sequence identity to photosystem I in a cysteine-containing loop, which is the putative binding site of the iron-sulfur center FX and in the preceding hydrophobic region. Our data imply a homodimeric organization of the reaction center. This is fundamentally different from photosystem I and most other photosynthetic reaction centers, where the reaction center core is composed of two similar but nonidentical subunits.
Original language | English (US) |
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Pages (from-to) | 7124-7128 |
Number of pages | 5 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 90 |
Issue number | 15 |
DOIs | |
State | Published - Aug 1 1993 |
Keywords
- Evolution
- Heliobacteria
- Photosynthesis
- Photosystem I
ASJC Scopus subject areas
- General