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A fresh look at the evolution and diversification of photochemical reaction centers.

Cardona T - Photosyn. Res. (2014)

Bottom Line: In this review, I reexamine the origin and diversification of photochemical reaction centers based on the known phylogenetic relations of the core subunits, and with the aid of sequence and structural alignments.Moreover, it becomes evident that the Acidobacteria and the Proteobacteria shared a more recent common phototrophic ancestor, and this is also likely for the Chloroflexi and the Cyanobacteria.The primordial phototrophic ancestor must have had both Type I and Type II reaction centers.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences, Imperial College London, Exhibition Road, London, SW7 2AZ, UK. t.cardona@imperial.ac.uk.

ABSTRACT
In this review, I reexamine the origin and diversification of photochemical reaction centers based on the known phylogenetic relations of the core subunits, and with the aid of sequence and structural alignments. I show, for example, that the protein folds at the C-terminus of the D1 and D2 subunits of Photosystem II, which are essential for the coordination of the water-oxidizing complex, were already in place in the most ancestral Type II reaction center subunit. I then evaluate the evolution of reaction centers in the context of the rise and expansion of the different groups of bacteria based on recent large-scale phylogenetic analyses. I find that the Heliobacteriaceae family of Firmicutes appears to be the earliest branching of the known groups of phototrophic bacteria; however, the origin of photochemical reaction centers and chlorophyll synthesis cannot be placed in this group. Moreover, it becomes evident that the Acidobacteria and the Proteobacteria shared a more recent common phototrophic ancestor, and this is also likely for the Chloroflexi and the Cyanobacteria. Finally, I argue that the discrepancies among the phylogenies of the reaction center proteins, chlorophyll synthesis enzymes, and the species tree of bacteria are best explained if both types of photochemical reaction centers evolved before the diversification of the known phyla of phototrophic bacteria. The primordial phototrophic ancestor must have had both Type I and Type II reaction centers.

No MeSH data available.


Related in: MedlinePlus

Comparison of a Type II reaction center subunit, D2 of Cyanobacterial Photosystem II (gray), and a Type I reaction center subunit (last five transmembrane helices) of the PsaB protein of Photosystem I (orange). a Overlap of D2 and PsaB; the FX cofactor from Photosystem I and the non-heme Fe2+ from Photosystem II have been displayed as spheres to show their relatives positions. b Overlap of some of the cofactors coordinated by D2 (gray) and PsaB (orange). The peripheral chlorophylls, ChlZ and ChlD, are conserved in these two subunits (Baymann et al. 2001). This histidine is also found in the sequences of all Type I reaction centers, with the exception of C. thermophilum and the anoxygenic Type II reaction centers. Its presence in Photosystem II implies that it was present in the most ancestral reaction center. The position of some of the chlorophylls, the quinones, FX, and non-heme Fe2+ is also very similar, yet the mode of coordination varies depending on the type of reaction center. The alignment of the subunits was made with the CEalign (Jia et al. 2004) plugging of Pymol (Molecular Graphics System, Version 1.5.0.4 Schrödinger, LLC)
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Fig2: Comparison of a Type II reaction center subunit, D2 of Cyanobacterial Photosystem II (gray), and a Type I reaction center subunit (last five transmembrane helices) of the PsaB protein of Photosystem I (orange). a Overlap of D2 and PsaB; the FX cofactor from Photosystem I and the non-heme Fe2+ from Photosystem II have been displayed as spheres to show their relatives positions. b Overlap of some of the cofactors coordinated by D2 (gray) and PsaB (orange). The peripheral chlorophylls, ChlZ and ChlD, are conserved in these two subunits (Baymann et al. 2001). This histidine is also found in the sequences of all Type I reaction centers, with the exception of C. thermophilum and the anoxygenic Type II reaction centers. Its presence in Photosystem II implies that it was present in the most ancestral reaction center. The position of some of the chlorophylls, the quinones, FX, and non-heme Fe2+ is also very similar, yet the mode of coordination varies depending on the type of reaction center. The alignment of the subunits was made with the CEalign (Jia et al. 2004) plugging of Pymol (Molecular Graphics System, Version 1.5.0.4 Schrödinger, LLC)

Mentions: Type I reaction centers are found as homodimers in anoxygenic phototrophic bacteria [e.g., Chlorobiales (Buttner et al. 1992), heliobacteria (Liebl et al. 1993), and C. thermophilum (Bryant et al. 2007)] and as heterodimers in members of the Cyanobacteria (Fish et al. 1985; Cantrell and Bryant 1987). In heliobacteria, the reaction center protein is named PshA, and the homologous proteins in the Chlorobiales and C. thermophilum are named PscA (Bryant 1994). In the phylum Cyanobacteria, the reaction center subunits are known as PsaA and PsaB. Type I reaction center proteins can be considered as having two domains: an antenna domain at the N-terminus encompassing the first six transmembrane helices, and a reaction center domain located at the C-terminus encompassing the last five transmembrane helices. The antenna domain has structural homology to the CP43 and CP47 subunits of Photosystem II (Fig. 1) (Vermaas 1994; Rutherford et al. 1996; Rutherford and Nitschke 1996; Mix et al. 2004; Vasil’ev and Bruce 2004), and the reaction center domain has structural homology to the core subunits of Type II reaction centers, L, M, D1, and D2 (Nitschke and Rutherford 1991; Fromme et al. 1996; Schubert et al. 1998; Baymann et al. 2001; Sadekar et al. 2006), see Fig. 2. Type I reaction centers are also characterized by having as terminal electron acceptors three consecutive Fe4S4 clusters, FX, FA, and FB (Fig. 1). FX is coordinated by two cysteine residues from each reaction center subunit, while FA and FB are located in an extrinsic protein that can be tightly or loosely bound (Scott et al. 1995; Nitschke et al. 1990a, b; Vassiliev et al. 2001; Heinnickel et al. 2005; Malkin 2006; Heinnickel et al. 2007; Jagannathan and Golbeck 2008; Romberger et al. 2010).Fig. 2


A fresh look at the evolution and diversification of photochemical reaction centers.

Cardona T - Photosyn. Res. (2014)

Comparison of a Type II reaction center subunit, D2 of Cyanobacterial Photosystem II (gray), and a Type I reaction center subunit (last five transmembrane helices) of the PsaB protein of Photosystem I (orange). a Overlap of D2 and PsaB; the FX cofactor from Photosystem I and the non-heme Fe2+ from Photosystem II have been displayed as spheres to show their relatives positions. b Overlap of some of the cofactors coordinated by D2 (gray) and PsaB (orange). The peripheral chlorophylls, ChlZ and ChlD, are conserved in these two subunits (Baymann et al. 2001). This histidine is also found in the sequences of all Type I reaction centers, with the exception of C. thermophilum and the anoxygenic Type II reaction centers. Its presence in Photosystem II implies that it was present in the most ancestral reaction center. The position of some of the chlorophylls, the quinones, FX, and non-heme Fe2+ is also very similar, yet the mode of coordination varies depending on the type of reaction center. The alignment of the subunits was made with the CEalign (Jia et al. 2004) plugging of Pymol (Molecular Graphics System, Version 1.5.0.4 Schrödinger, LLC)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4582080&req=5

Fig2: Comparison of a Type II reaction center subunit, D2 of Cyanobacterial Photosystem II (gray), and a Type I reaction center subunit (last five transmembrane helices) of the PsaB protein of Photosystem I (orange). a Overlap of D2 and PsaB; the FX cofactor from Photosystem I and the non-heme Fe2+ from Photosystem II have been displayed as spheres to show their relatives positions. b Overlap of some of the cofactors coordinated by D2 (gray) and PsaB (orange). The peripheral chlorophylls, ChlZ and ChlD, are conserved in these two subunits (Baymann et al. 2001). This histidine is also found in the sequences of all Type I reaction centers, with the exception of C. thermophilum and the anoxygenic Type II reaction centers. Its presence in Photosystem II implies that it was present in the most ancestral reaction center. The position of some of the chlorophylls, the quinones, FX, and non-heme Fe2+ is also very similar, yet the mode of coordination varies depending on the type of reaction center. The alignment of the subunits was made with the CEalign (Jia et al. 2004) plugging of Pymol (Molecular Graphics System, Version 1.5.0.4 Schrödinger, LLC)
Mentions: Type I reaction centers are found as homodimers in anoxygenic phototrophic bacteria [e.g., Chlorobiales (Buttner et al. 1992), heliobacteria (Liebl et al. 1993), and C. thermophilum (Bryant et al. 2007)] and as heterodimers in members of the Cyanobacteria (Fish et al. 1985; Cantrell and Bryant 1987). In heliobacteria, the reaction center protein is named PshA, and the homologous proteins in the Chlorobiales and C. thermophilum are named PscA (Bryant 1994). In the phylum Cyanobacteria, the reaction center subunits are known as PsaA and PsaB. Type I reaction center proteins can be considered as having two domains: an antenna domain at the N-terminus encompassing the first six transmembrane helices, and a reaction center domain located at the C-terminus encompassing the last five transmembrane helices. The antenna domain has structural homology to the CP43 and CP47 subunits of Photosystem II (Fig. 1) (Vermaas 1994; Rutherford et al. 1996; Rutherford and Nitschke 1996; Mix et al. 2004; Vasil’ev and Bruce 2004), and the reaction center domain has structural homology to the core subunits of Type II reaction centers, L, M, D1, and D2 (Nitschke and Rutherford 1991; Fromme et al. 1996; Schubert et al. 1998; Baymann et al. 2001; Sadekar et al. 2006), see Fig. 2. Type I reaction centers are also characterized by having as terminal electron acceptors three consecutive Fe4S4 clusters, FX, FA, and FB (Fig. 1). FX is coordinated by two cysteine residues from each reaction center subunit, while FA and FB are located in an extrinsic protein that can be tightly or loosely bound (Scott et al. 1995; Nitschke et al. 1990a, b; Vassiliev et al. 2001; Heinnickel et al. 2005; Malkin 2006; Heinnickel et al. 2007; Jagannathan and Golbeck 2008; Romberger et al. 2010).Fig. 2

Bottom Line: In this review, I reexamine the origin and diversification of photochemical reaction centers based on the known phylogenetic relations of the core subunits, and with the aid of sequence and structural alignments.Moreover, it becomes evident that the Acidobacteria and the Proteobacteria shared a more recent common phototrophic ancestor, and this is also likely for the Chloroflexi and the Cyanobacteria.The primordial phototrophic ancestor must have had both Type I and Type II reaction centers.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences, Imperial College London, Exhibition Road, London, SW7 2AZ, UK. t.cardona@imperial.ac.uk.

ABSTRACT
In this review, I reexamine the origin and diversification of photochemical reaction centers based on the known phylogenetic relations of the core subunits, and with the aid of sequence and structural alignments. I show, for example, that the protein folds at the C-terminus of the D1 and D2 subunits of Photosystem II, which are essential for the coordination of the water-oxidizing complex, were already in place in the most ancestral Type II reaction center subunit. I then evaluate the evolution of reaction centers in the context of the rise and expansion of the different groups of bacteria based on recent large-scale phylogenetic analyses. I find that the Heliobacteriaceae family of Firmicutes appears to be the earliest branching of the known groups of phototrophic bacteria; however, the origin of photochemical reaction centers and chlorophyll synthesis cannot be placed in this group. Moreover, it becomes evident that the Acidobacteria and the Proteobacteria shared a more recent common phototrophic ancestor, and this is also likely for the Chloroflexi and the Cyanobacteria. Finally, I argue that the discrepancies among the phylogenies of the reaction center proteins, chlorophyll synthesis enzymes, and the species tree of bacteria are best explained if both types of photochemical reaction centers evolved before the diversification of the known phyla of phototrophic bacteria. The primordial phototrophic ancestor must have had both Type I and Type II reaction centers.

No MeSH data available.


Related in: MedlinePlus