NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Evolution of heliobacteria: implications for photosynthetic reaction center complexesThe evolutionary position of the heliobacteria, a group of green photosynthetic bacteria with a photosynthetic apparatus functionally resembling Photosystem I of plants and cyanobacteria, has been investigated with respect to the evolutionary relationship to Gram-positive bacteria and cyanobacteria. On the basis of 16S rRNA sequence analysis, the heliobacteria appear to be most closely related to Gram-positive bacteria, but also an evolutionary link to cyanobacteria is evident. Interestingly, a 46-residue domain including the putative sixth membrane-spanning region of the heliobacterial reaction center protein show rather strong similarity (33% identity and 72% similarity) to a region including the sixth membrane-spanning region of the CP47 protein, a chlorophyll-binding core antenna polypeptide of Photosystem II. The N-terminal half of the heliobacterial reaction center polypeptide shows a moderate sequence similarity (22% identity over 232 residues) with the CP47 protein, which is significantly more than the similarity with the Photosystem I core polypeptides in this region. An evolutionary model for photosynthetic reaction center complexes is discussed, in which an ancestral homodimeric reaction center protein (possibly resembling the heliobacterial reaction center protein) with 11 membrane-spanning regions per polypeptide has diverged to give rise to the core of Photosystem I, Photosystem II, and of the photosynthetic apparatus in green, purple, and heliobacteria.
Document ID
20040089784
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Vermaas, W. F.
(Arizona State University Tempe 85287-1601, United States)
Blankenship, R. E.
Date Acquired
August 21, 2013
Publication Date
January 1, 1994
Publication Information
Publication: Photosynthesis research
Volume: 41
ISSN: 0166-8595
Subject Category
Exobiology
Funding Number(s)
CONTRACT_GRANT: DE-FG02-88ER13969
Distribution Limits
Public
Copyright
Other
Keywords
NASA Program Exobiology
NASA Discipline Number 52-30
Non-NASA Center
NASA Discipline Exobiology

Available Downloads

There are no available downloads for this record.
No Preview Available