Tracking the molecular evolution of photosynthesis through characterization of atomic contents of the photosynthetic units.
ABSTRACT Oxygen molecules have a great impact on protein evolution. We have performed a comparative study of key photosynthetic proteins in order to seek the answer to the question; did the evolutionary substitution of oxygen- and nitrogen-containing residues in the photosynthetic proteins correspond to nutrient constraints and metabolic optimization? The D1 peptide in RC II complexes has higher oxygen-containing amino acid residues and PufL/PufM have lower oxygen content in their peptides. In this article, we also discuss the possible influences of micro-environment and the available nutrients on the protein structure and their atomic distribution.
- SourceAvailable from: sciencedirect.com[show abstract] [hide abstract]
ABSTRACT: In integral membrane proteins, regions that span the lipid bilayer alternate with regions that are exposed on either side of the membrane. For proteins from the plasma membrane of both prokaryotic and eukaryotic cells it has been shown that the exposed parts follow a 'positive-inside rule': on average, segments that are translocated across the membrane have a 2-4-fold lower frequency of positively charged residues than non-translocated segments. We now present an analysis of proteins from the thylakoid membrane of chloroplasts. It is shown that these proteins have the same charge asymmetry as has been reported for proteins from other membrane systems, with their more highly charged regions facing the stromal compartment.FEBS Letters 05/1991; 282(1):41-6. · 3.58 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Photosynthesis is an ancient process on Earth. Chemical evidence and recent fossil finds indicate that cyanobacteria existed 2.5-2.6 billion years (Ga) ago, and these were certainly preceded by a variety of forms of anoxygenic photosynthetic bacteria. Carbon isotope data suggest autotrophic carbon fixation was taking place at least a billion years earlier. However, the nature of the earliest photosynthetic organisms is not well understood. The major elements of the photosynthetic apparatus are the reaction centers, antenna complexes, electron transfer complexes and carbon fixation machinery. These parts almost certainly have not had the same evolutionary history in all organisms, so that the photosynthetic apparatus is best viewed as a mosaic made up of a number of substructures each with its own unique evolutionary history. There are two schools of thought concerning the origin of reaction centers and photosynthesis. One school pictures the evolution of reaction centers beginning in the prebiotic phase while the other school sees reaction centers evolving later from cytochrome b in bacteria. Two models have been put forth for the subsequent evolution of reaction centers in proteobacteria, green filamentous (non-sulfur) bacteria, cyanobacteria, heliobacteria and green sulfur bacteria. In the selective loss model the most recent common ancestor of all subsequent photosynthetic systems is postulated to have contained both RC1 and RC2. The evolution of reaction centers in proteobacteria and green filamentous bacteria resulted from the loss of RC1, while the evolution of reaction centers in heliobacteria and green sulfur bacteria resulted from the loss of RC2. Both RC1 and RC2 were retained in the cyanobacteria. In the fusion model the most recent common ancestor is postulated to have given rise to two lines, one containing RC1 and the other containing RC2. The RC1 line gave rise to the reaction centers of heliobacteria and green sulfur bacteria, and the RC2 line led to the reaction centers of proteobacteria and green filamentous bacteria. The two reaction centers of cyanobacteria were the result of a genetic fusion of an organism containing RC1 and an organism containing RC2. The evolutionary histories of the various classes of antenna/light-harvesting complexes appear to be completely independent. The transition from anoxygenic to oxygenic photosynthesis took place when the cyanobacteria learned how to use water as an electron donor for carbon dioxide reduction. Before that time hydrogen peroxide may have served as a transitional donor, and before that, ferrous iron may have been the original source of reducing power.Photosynthesis Research 02/2004; 80(1-3):373-86. · 3.15 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Two hypotheses account for the evolution of the inner antenna light-harvesting proteins of oxygenic photosynthesis in cyanobacteria, algae, and plants: one in which the CP43 protein of photosytem II gave rise to the extrinsic CP43-like antennas of cyanobacteria (i.e. IsiA and Pcb proteins), as a late development, and the other in which CP43 and CP43-like proteins derive from an ancestral protein. In order to determine which of these hypotheses is most likely, we analyzed the family of antenna proteins by a variety of phylogenetic techniques, using alignments of the six common membrane-spanning helices, constructed using information on the antenna proteins' three-dimensional structure, and surveyed for evidence of factors that might confound inference of a correct phylogeny. The first hypothesis was strongly supported. As a consequence, we conclude that the ancestral photosynthetic apparatus, with 11 membrane-spanning helices, split at an early stage during evolution to form, on the one hand, the reaction center of photosystem II and, on the other hand, the ancestor of inner antenna proteins, CP43 (PsbC) and CP47 (PsbB). Only much later in evolution did the CP43 lineage give rise to the CP43' proteins (IsiA and Pcb) of cyanobacteria.Journal of Molecular Evolution 04/2007; 64(3):321-31. · 2.15 Impact Factor