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Abstract
Reduced inorganic sulfur compounds are oxidized by members of the domains Archaea and Bacteria. These compounds are used as electron donors for anaerobic phototrophic and aerobic chemotrophic growth, and are mostly oxidized to sulfate. Different enzymes mediate the conversion of various reduced sulfur compounds. Their physiological function in sulfur oxidation is considered (i) mostly from the biochemical characterization of the enzymatic reaction, (ii) rarely from the regulation of their formation, and (iii) only in a few cases from the mutational gene inactivation and characterization of the resulting mutant phenotype. In this review the sulfur-metabolizing reactions of selected phototrophic and of chemotrophic prokaryotes are discussed. These comprise an archaeon, a cyanobacterium, green sulfur bacteria, and selected phototrophic and chemotrophic proteobacteria. The genetic systems are summarized which are presently available for these organisms, and which can be used to study the molecular basis of their dissimilatory sulfur metabolism. Two groups of thiobacteria can be distinguished: those able to grow with tetrathionate and other reduced sulfur compounds, and those unable to do so. This distinction can be made irrespective of their phototrophic or chemotrophic metabolism, neutrophilic or acidophilic nature, and may indicate a mechanism different from that of thiosulfate oxidation. However, the core enzyme for tetrathionate oxidation has not been identified so far. Several phototrophic bacteria utilize hydrogen sulfide, which is considered to be oxidized by flavocytochrome c owing to its in vitro activity. However, the function of flavocytochrome c in vivo may be different, because it is missing in other hydrogen sulfide-oxidizing bacteria, but is present in most thiosulfate-oxidizing bacteria. A possible function of flavocytochrome c is discussed based on biophysical studies, and the identification of a flavocytochrome in the operon encoding enzymes involved in thiosulfate oxidation of Paracoccus denitrificans. Adenosine-5'-phosphosulfate reductase thought to function in the 'reverse' direction in different phototrophic and chemotrophic sulfur-oxidizing bacteria was analysed in Chromatium vinosum. Inactivation of the corresponding gene does not affect the sulfite-oxidizing ability of the mutant. This result questions the concept of its 'reverse' function, generally accepted for over three decades.
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Affiliation(s)
- C G Friedrich
- Lehrstuhl für Technische Mikrobiologie, Fachbereich Chemietechnik, Universität Dortmund, Germany
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52
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Dastoor FP, Forrest ME, Beatty JT. Cloning, sequencing, and oxygen regulation of the Rhodobacter capsulatus alpha-ketoglutarate dehydrogenase operon. J Bacteriol 1997; 179:4559-66. [PMID: 9226266 PMCID: PMC179292 DOI: 10.1128/jb.179.14.4559-4566.1997] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The Rhodobacter capsulatus sucA, sucB, and lpd genes, which encode the alpha-ketoglutarate dehydrogenase (E1o), the dihydrolipoamide succinyltransferase (E2o), and the dihydrolipoamide dehydrogenase (E3) components of the alpha-ketoglutarate dehydrogenase complex (KGD), respectively, were cloned, sequenced, and used for regulatory analyses. The KGD enzymatic activity was greater in cells grown under aerobic, respiratory growth conditions than under anaerobic, photosynthetic conditions. Similarly, the sucA gene was transcribed differentially, leading to a greater accumulation of sucA mRNAs under respiratory growth conditions than under photosynthetic conditions, although differential rates of mRNA decay could also contribute to the different amounts of sucA mRNAs under these two growth conditions. The sucA promoter was located about 4 kb upstream of the 5' end of the sucA gene, and transcripts greater than 9.5 kb hybridized to a sucA probe, suggesting the presence of an operon that produces a polycistronic mRNA. Thus, these genes seem to be expressed as an unstable primary transcript, and we speculate that posttranscriptional processes control the stoichiometry of KGD proteins.
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Affiliation(s)
- F P Dastoor
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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53
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Inui M, Vertès AA, Yukawa H. Reverse catabolite repression and the regulation of CO2 fixation in Rhodobacter and related bacteria. Res Microbiol 1996; 147:562-6. [PMID: 9084770 DOI: 10.1016/0923-2508(96)84012-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- M Inui
- Research Institute of Innovative Technology for the Earth, Kyoto, Japan
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54
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Affiliation(s)
- C Sasikala
- Department of Botany, Osmania University, Hyderabad, India
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55
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Qian Y, Tabita FR. A global signal transduction system regulates aerobic and anaerobic CO2 fixation in Rhodobacter sphaeroides. J Bacteriol 1996; 178:12-8. [PMID: 8550404 PMCID: PMC177615 DOI: 10.1128/jb.178.1.12-18.1996] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Complementation of a mutant of Rhodobacter sphaeroides defective in photosynthetic CO2 reduction led to the identification of a gene which encodes a protein that is related to a class of sensor kinases involved in bacterial signal transduction. The nucleotide sequence and deduced amino acid sequence led to the finding that the gene which complemented the mutant is the regB (prrB) gene, previously isolated from both R. sphaeroides and Rhodobacter capsulatus and shown to regulate the anaerobic expression of structural genes required for the synthesis of the reaction center and light-harvesting systems of these organisms. The current investigation indicates that in addition to its role in the regulation of photosystem biosynthesis, regB (prrB) of R. sphaeroides is intimately involved in the positive regulation of the cbbI and cbbII Calvin cycle CO2 fixation operons. In addition to regulating the expression of structural genes encoding enzymes of the primary pathway for CO2 fixation in R. sphaeroides, regB was also found to be required for the expression of a gene(s) important for the putative alternative CO2 fixation pathway(s) of this organism. A mutation in regB also blocked expression of structural genes of the cbb regulon in a strain of R. sphaeroides capable of aerobic CO2-dependent growth in the dark. It is thus apparent that regB is part of a two-component system and encodes a sensor kinase involved in the global regulation of both anoxygenic light-dependent- and oxygenic light-independent CO2 fixation as well as anoxygenic photosystem biosynthesis.
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Affiliation(s)
- Y Qian
- Ohio State Biochemistry, Ohio State University, Columbus 43210-1292, USA
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56
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Paoli GC, Morgan NS, Tabita FR, Shively JM. Expression of the cbbLcbbS and cbbM genes and distinct organization of the cbb Calvin cycle structural genes of Rhodobacter capsulatus. Arch Microbiol 1995; 164:396-405. [PMID: 8588741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Rhodobacter capsulatus fixes CO2 via the Calvin reductive pentose phosphate pathway and, like some other nonsulfur purple bacteria, is known to synthesize two distinct structural forms of ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO). Cosmid clones that hybridized to form I (cbbLcbbS) and form II (cbbM) RubisCO gene probes were isolated from a genomic library of R. capsulatus strain SB1003. Southern blotting and hybridization analysis with gene-specific probes derived from Rhodobacter sphaeroides revealed that R. capsulatus cbbM is clustered with genes encoding other enzymes of the Calvin cycle, including fructose 1,6/sedoheptulose 1,7-bisphosphatase (cbbF), phosphoribulokinase (cbbP), transketolase (cbbT), glyceraldehyde-3-phosphate dehydrogenase (cbbG), and fructose 1,6-bisphosphate aldolase (cbbA), as well as a gene (cbbR) encoding a divergently transcribed LysR-type regulatory protein. Surprisingly, a cosmid clone containing the R. capsulatus form I RubisCO genes (cbbL and cbbS) failed to hybridize to the other cbb structural gene probes, unlike the situation with the closely related organism R. sphaeroides. The form I and form II RubisCO genes were cloned into pUC-derived vectors and were expressed in Escherichia coli to yield active recombinant enzyme in each case. Complementation of a RubisCO-deletion strain of R. sphaeroides to photosynthetic growth by R. capsulatus cbbLcbbS or cbbM was achieved using the broad host-range vector, pRK415, and R. sphaeroides expression vector pRPS-1.
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Affiliation(s)
- G C Paoli
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
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57
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Paoli GC, Morgan NS, Tabita FR, Shively JM. Expression of thecbbLcbbS andcbbM genes and distinct organization of thecbb Calvin cycle structural genes ofRhodobacter capsulatus. Arch Microbiol 1995. [DOI: 10.1007/bf02529737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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58
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Bollivar DW, Elliott T, Beale SI. Anaerobic protoporphyrin biosynthesis does not require incorporation of methyl groups from methionine. J Bacteriol 1995; 177:5778-83. [PMID: 7592323 PMCID: PMC177398 DOI: 10.1128/jb.177.20.5778-5783.1995] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
It was recently reported (H. Akutsu, J.-S. Park, and S. Sano, J. Am. Chem. Soc. 115:12185-12186, 1993) that in the strict anaerobe Desulfovibrio vulgaris methyl groups from exogenous L-methionine are incorporated specifically into the 1 and 3 positions (Fischer numbering system) on the heme groups of cytochrome c3. It was suggested that under anaerobic conditions, protoporphyrin IX biosynthesis proceeds via a novel pathway that does not involve coproporphyrinogen III as a precursor but instead may use precorrin-2 (1,3-dimethyluroporphyrinogen III), a siroheme and vitamin B12 precursor which is known to be derived from uroporphyrinogen III via methyl transfer from S-adenosyl-L-methionine. We have critically tested this hypothesis by examining the production of protoporphyrin IX-based tetrapyrroles in the presence of exogenous [14C]methyl-L-methionine under anaerobic conditions in a strict anaerobe (Chlorobium vibrioforme) and a facultative anaerobe (Rhodobacter capsulatus). In both organisms, 14C was incorporated into the bacteriochlorophyll precursor, Mg-protoporphyrin IX monomethyl ester. However, most of the label was lost upon base hydrolysis of this compound to yield Mg-protoporphyrin IX. These results indicate that although the administered [14C]methyl-L-methionine was taken up, converted into S-adenosyl-L-methionine, and used for methyl transfer reactions, including methylation of the 6-propionate of Mg-protoporphyrin IX, methyl groups were not transferred to the porphyrin nucleus of Mg-protoporphyrin IX. In other experiments, a cysG strain of Salmonella typhimurium, which cannot synthesize precorrin-2 because the gene encoding the enzyme that catalyzes methylation of uroporphyrinogen III at positions 1 and 3 is disrupted, was capable of heme-dependent anaerobic nitrate respiration and growth on the nonfermentable substrate glycerol, indicating that anaerobic biosynthesis of protoporphyrin IX-based hemes does not require the ability to methylate uroporphyrinogen III. Together, these results indicate that incorporation of L-methionine-deprived methyl groups into porphyrins or their precursors is not generally necessary for the anaerobic biosynthesis of protoporphyrin IX-based tetrapyrroles.
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Affiliation(s)
- D W Bollivar
- Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA
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59
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Kimble LK, Mandelco L, Woese CR, Madigan MT. Heliobacterium modesticaldum, sp. nov., a thermophilic heliobacterium of hot springs and volcanic soils. Arch Microbiol 1995. [DOI: 10.1007/bf00393378] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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60
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61
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Naud I, Vinçon M, Garin J, Gaillard J, Forest E, Jouanneau Y. Purification of a sixth ferredoxin from Rhodobacter capsulatus. Primary structure and biochemical properties. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 222:933-9. [PMID: 8026503 DOI: 10.1111/j.1432-1033.1994.tb18942.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A new ferredoxin has been purified from the photosynthetic bacterium Rhodobacter capsulatus. It is the sixth ferredoxin to be isolated from this bacterium and it was called FdVI. Its primary structure was established based on amino acid sequence analysis of the protein and of peptides derived from it. It is composed of 106 residues including five cysteines. The calculated mass of the polypeptide is 11,402.6 Da which matches the experimental value determined by electrospray mass spectrometry. Amino acid sequence comparison revealed that ferredoxin VI (FdVI) is strikingly similar to a ferredoxin from Caulobacter crescentus and to the putidaredoxin from Pseudomonas putida. FdVI exhibited an ultraviolet-visible absorption spectrum typical for a [2Fe-2S] ferredoxin. EPR spectroscopy of the reduced protein showed a nearly axial signal similar to that of mitochondrial and P. putida ferredoxins. FdVI is biosynthesized in cells growing anaerobically under either nitrogen-sufficient or nitrogen-deficient conditions. Although the function of FdVI is unknown, its structural resemblance to [2Fe-2S] ferredoxins known to transfer electrons to oxygenases such as P-450 cytochromes, suggests that FdVI may have a similar role in R. capsulatus.
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Affiliation(s)
- I Naud
- Laboratoire de Biochimie Microbienne (CNRS URA 1130 alliée à l'INSERM), Département de Biologie Moléculaire et Structurale, Grenoble, France
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62
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Gest H. A microbiologist's odyssey: Bacterial viruses to photosynthetic bacteria. PHOTOSYNTHESIS RESEARCH 1994; 40:129-146. [PMID: 24311283 DOI: 10.1007/bf00019331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/1994] [Accepted: 01/13/1994] [Indexed: 06/02/2023]
Abstract
Perspective can be defined as the relationships or relative importance of facts or matters from any special point of view. Thus, my Personal perspective reflects the threads I followed in a 50-year journey of research in the complex tapestry of bioenergetics and various aspects of microbial metabolism. An early interest in biochemical and microbial evolution led to the fertile hunting grounds of anoxygenic photosynthetic bacteria. Viewed as a physiological class, these organisms show remarkable metabolic versatility in that certain individual species are capable of using all the known major types of energy conversion (photosynthetic, respiratory, and fermentative) to support growth. Since such anoxyphototrophs are readily amenable to molecular genetic/biological manipulation, it can be expected that they will eventually provide important clues for unraveling the evolutionary relationships of the several kinds of energy conversion. I gradually came to believe that understanding the evolution of phototrophs would require detailed knowledge not only of how light is converted to chemical energy, but also of a) pathways of monomer production from extracellular sources of carbon and nitrogen and b) mechanisms cells use for integrating ATP regeneration with the energy-requiring biosyntheses of biological macromolecules. Serendipic observation of photoproduction of H2 from organic compounds by Rhodospirillum rubrum in 1949 led to discovery of N2 fixation by anoxyphototrophs, and this capacity was later exploited for the isolation of hitherto unknown species of photosynthetic prokaryotes, including the heliobacteria. Recent studies on the reaction centers of the heliobacteria suggest the possibility that these bacteria are descendents of early phototrophs that gave rise to oxygenic photosynthetic organisms.
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Affiliation(s)
- H Gest
- Photosynthetic Bacteria Group, Department of Biology, Indiana University, 47405, Bloomington, IN, USA
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63
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McEwan AG. Photosynthetic electron transport and anaerobic metabolism in purple non-sulfur phototrophic bacteria. Antonie Van Leeuwenhoek 1994; 66:151-64. [PMID: 7747929 DOI: 10.1007/bf00871637] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Purple non-sulfur phototrophic bacteria, exemplified by Rhodobacter capsulatus and Rhodobacter sphaeroides, exhibit a remarkable versatility in their anaerobic metabolism. In these bacteria the photosynthetic apparatus, enzymes involved in CO2 fixation and pathways of anaerobic respiration are all induced upon a reduction in oxygen tension. Recently, there have been significant advances in the understanding of molecular properties of the photosynthetic apparatus and the control of the expression of genes involved in photosynthesis and CO2 fixation. In addition, anaerobic respiratory pathways have been characterised and their interaction with photosynthetic electron transport has been described. This review will survey these advances and will discuss the ways in which photosynthetic electron transport and oxidation-reduction processes are integrated during photoautotrophic and photoheterotrophic growth.
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Affiliation(s)
- A G McEwan
- Department of Microbiology, University of Queensland, Brisbane, Australia
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64
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Eraso JM, Kaplan S. prrA, a putative response regulator involved in oxygen regulation of photosynthesis gene expression in Rhodobacter sphaeroides. J Bacteriol 1994; 176:32-43. [PMID: 8282708 PMCID: PMC205011 DOI: 10.1128/jb.176.1.32-43.1994] [Citation(s) in RCA: 192] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A new locus, prrA, involved in the regulation of photosynthesis gene expression in response to oxygen, has been identified in Rhodobacter sphaeroides. Inactivation of prrA results in the absence of photosynthetic spectral complexes. The prrA gene product has strong homology to response regulators associated with signal transduction in other prokaryotes. When prrA is present in multiple copies, cells produce light-harvesting complexes under aerobic growth conditions, suggesting that prrA affects photosynthesis gene expression positively in response to oxygen deprivation. Analysis of the expression of puc::lacZ fusions in wild-type and PrrA- cells revealed a substantial decrease in LacZ expression in the absence of prrA under all conditions of growth, especially when cells were grown anaerobically in the dark in the presence of dimethyl sulfoxide. Northern (RNA) and slot blot hybridizations confirmed the beta-galactoside results for puc and revealed additional positive regulation of puf, puhA, and cycA by PrrA. The effect of truncated PrrA on photosynthesis gene expression in the presence of low oxygen levels can be explained by assuming that PrrA may be effective as a multimer. PrrA was found to act on the downstream regulatory sequences (J. K. Lee and S. Kaplan, J. Bacteriol. 174:1146-1157, 1992) of the puc operon regulatory region. Finally, two spontaneous prrA mutations that abolish prrA function by changing amino acids in the amino-terminal domain of the protein were isolated.
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Affiliation(s)
- J M Eraso
- Department of Microbiology and Molecular Genetics, University of Texas Medical School, Houston 77030
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65
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Wang X, Falcone DL, Tabita FR. Reductive pentose phosphate-independent CO2 fixation in Rhodobacter sphaeroides and evidence that ribulose bisphosphate carboxylase/oxygenase activity serves to maintain the redox balance of the cell. J Bacteriol 1993; 175:3372-9. [PMID: 8501041 PMCID: PMC204734 DOI: 10.1128/jb.175.11.3372-3379.1993] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Whole-cell CO2 fixation and ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) activity were determined in Rhodobacter sphaeroides wild-type and mutant strains. There is no obvious difference in the levels of whole-cell CO2 fixation for the wild type, a form I RubisCO deletion mutant, and a form II RubisCO deletion mutant. No ribulose 1,5-bisphosphate-dependent CO2 fixation was detected in a form I-form II RubisCO double-deletion mutant (strain 16) or strain 16PHC, a derivative from strain 16 which was selected for the ability to grow photoheterotrophically with CO2 as an electron acceptor. However, significant levels of whole-cell CO2 fixation were detected in both strains 16 and 16PHC. Strain 16PHC exhibited CO2 fixation rates significantly higher than those of strain 16; the rates found for strain 16PHC were 30% of the level found in photoheterotrophically grown wild-type strain HR containing both form I and form II RubisCO and 10% of the level of the wild-type strain grown photolithoautotrophically. Strain 16PHC could not grow photolithoautotrophically in a CO2-H2 atmosphere; however, CO2 fixation catalyzed by photoheterotrophically grown strain 16PHC was repressed by addition of the alternate electron acceptor dimethyl sulfoxide. Dimethyl sulfoxide addition also influenced RubisCO activity under photolithoautotrophic conditions; 40 to 70% of the RubisCO activity was reduced without significantly influencing growth. Strain 16PHC and strain 16 contain nearly equivalent but low levels of pyruvate carboxylase, indicating that CO2 fixation enzymes other than pyruvate carboxylase contribute to the ability of strain 16PHC to grow with CO2 as an electron acceptor.
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Affiliation(s)
- X Wang
- Department of Microbiology, Ohio State University, Columbus 43210-1192
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66
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Wu LF, Mandrand MA. Microbial hydrogenases: primary structure, classification, signatures and phylogeny. FEMS Microbiol Rev 1993; 10:243-69. [PMID: 8318259 DOI: 10.1111/j.1574-6968.1993.tb05870.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Thirty sequenced microbial hydrogenases are classified into six classes according to sequence homologies, metal content and physiological function. The first class contains nine H2-uptake membrane-bound NiFe-hydrogenases from eight aerobic, facultative anaerobic and anaerobic bacteria. The second comprises four periplasmic and two membrane-bound H2-uptake NiFe(Se)-hydrogenases from sulphate-reducing bacteria. The third consists of four periplasmic Fe-hydrogenases from strict anaerobic bacteria. The fourth contains eight methyl-viologen- (MV), factor F420- (F420) or NAD-reducing soluble hydrogenases from methanobacteria and Alcaligenes eutrophusH16. The fifth is the H2-producing labile hydrogenase isoenzyme 3 of Escherichia coli. The sixth class contains two soluble tritium-exchange hydrogenases of cyanobacteria. The results of sequence comparison reveal that the 30 hydrogenases have evolved from at least three different ancestors. While those of class I, II, IV and V hydrogenases are homologous, i.e. sharing the same evolutionary origin, both class III and VI hydrogenases are neither related to each other nor to the other classes. Sequence comparison scores, hierarchical cluster structures and phylogenetic trees show that class II falls into two distinct clusters composed of NiFe- and NiFeSe-hydrogenases, respectively. These results also reveal that class IV comprises three distinct clusters: MV-reducing, F420-reducing and NAD-reducing hydrogenases. Specific signatures of the six classes of hydrogenases as well as some subclusters have been detected. Analyses of motif compositions indicate that all hydrogenases, except those of class VI, must contain some common motifs probably participating in the formation of hydrogen activation domains and electron transfer domains. The regions of hydrogen activation domains are highly conserved and can be divided into two categories. One corresponds to the 'nickel active center' of NiFe(Se)-hydrogenases. It consists of two possible specific nickel-binding motifs, RxCGxCxxxH and DPCxxCxxH, located at the N- and C-termini of so-called large subunits in the dimeric hydrogenases, respectively. The other is the H-cluster of the Fe-hydrogenases. It might comprise three motifs on the C-terminal half of the large subunits. However, the motifs corresponding to the putative electron transfer domains, as well as their polypeptides chains, are poorly or even not at all conserved. They are present essentially on the small subunits in NiFe-hydrogenases. Some of these motifs resemble the typical ferredoxin-like Fe-S cluster binding site.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- L F Wu
- Laboratoire de Génétique Moléculaire des Microorganismes, CNRS URA 1486, INSA, Villeurbanne, France
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67
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Willison JC. Biochemical genetics revisited: the use of mutants to study carbon and nitrogen metabolism in the photosynthetic bacteria. FEMS Microbiol Rev 1993; 10:1-38. [PMID: 8431308 DOI: 10.1111/j.1574-6968.1993.tb05862.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The biochemical genetics approach is defined as the use of mutants, in comparative studies with the wild-type, to obtain information about biochemical and physiological processes in complex metabolic systems. This approach has been used extensively, for example in studies on the bioenergetics of the photosynthetic bacteria, but has been applied less frequently to studies of intermediary carbon and nitrogen metabolism in phototrophic organisms. Several important processes in photosynthetic bacteria--the regulation of nitrogenase synthesis and activity, the control of intracellular redox balance during photoheterotrophic growth, and chemotaxis--have been shown to involve metabolism. However, current understanding of carbon and nitrogen metabolism in these organisms is insufficient to allow a complete understanding of these phenomena. The purpose of the present review is to give an overview of carbon and nitrogen metabolism in the photosynthetic bacteria, with particular emphasis on work carried out with mutants, and to indicate areas in which the biochemical genetics approach could be applied successfully. In particular, it will be argued that, in the case of Rhodobacter capsulatus and Rb. sphaeroides, two species which are fast-growing, possess a versatile metabolism, and have been extensively studied genetically, it should be possible to obtain a complete, integrated description of carbon and nitrogen metabolism, and to undertake a qualitative and quantitative analysis of the flow of carbon and reducing equivalents during photoheterotrophic growth. This would require a systematic biochemical genetic study employing techniques such as HPLC, NMR, and mass spectrometry, which are briefly discussed. The review is concerned mainly with Rb. capsulatus and Rb. sphaeroides, since most studies with mutants have been carried out with these organisms. However, where possible, a comparison is made with other species of purple non-sulphur bacteria and with purple and green sulphur bacteria, and recent literature relevant to these organisms has been cited.
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Affiliation(s)
- J C Willison
- Département de Biologie Moléculaire et Structurale, Centre d'Etudes Nucléaires de Grenoble, France
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68
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Anoxygenic Phototrophic Bacteria: Physiology and Advances in Hydrogen Production Technology. ADVANCES IN APPLIED MICROBIOLOGY 1993. [DOI: 10.1016/s0065-2164(08)70217-x] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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69
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McShea A, Woodward AM, Kell DB. Non-linear dielectric properties of Rhodobacter capsulatus. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0302-4598(92)80068-r] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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70
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Khanna P, Rajkumar B, Jothikumar N. Anoxygenic degradation of aromatic substances byRhodopseudomonas palustris. Curr Microbiol 1992; 25:63-7. [PMID: 1369192 DOI: 10.1007/bf01570961] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Three strains of the phototrophic purple nonsulfur bacterium Rhodopseudomonas palustris were isolated from different environments and were evaluated for their aromatic degradative potential under phototrophic conditions. All three strains (PFR1, PNR4, and MRL1) utilized benzoate, 4-hydroxybenzoate, 4-aminobenzoate, 4-aminophenol, cinnamate, ferulate, phloroglucinol, and 4-dimethylaminobenzaldehyde in the absence of exogenous CO2. 4-Aminobenzoate and 4-aminophenol served as a carbon and nitrogen source for all the three strains. Utilization of 4-aminophenol was enhanced in the presence of 4-hydroxybenzoate. Salicylate was utilized by PFR1 and MRL1 strains, and phenol was utilized by the MRL1 strain only in the presence of exogenous CO2.
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Affiliation(s)
- P Khanna
- National Environmental Engineering Research Institute, Jawaharlal Nehru Marg, Nagpur, India
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71
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72
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Chen JC, Mortenson LE. Two open reading frames (ORFs) identified near the hydrogenase structural genes in Azotobacter vinelandii, the first ORF may encode for a polypeptide similar to rubredoxins. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1131:122-4. [PMID: 1581355 DOI: 10.1016/0167-4781(92)90111-c] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Sequencing of 744 base pairs (bp) of a cloned section of DNA from Azotobacter vinelandii reveals two complete, closely-spaced open reading frames (ORF1 and ORF2). Both ORFs are transcribed from the same DNA strand as that of the structural genes for hydrogenase (hoxK and hoxG, Menon, A.L. et al. (1990) Gene 96, 67-74), and are located downstream from the latter genes. The distance between the end of hoxG and the beginning of ORF1 is approx. 3.0 kilobases (kb). Most of the deduced amino acid sequence of ORF1 shares high homology with rubredoxin sequences. Some of the deduced amino acid sequence of ORF2 shares homology with that of a reported partial ORF from Rhodobacter capsulatus, ORF located within a region of DNA required for dihydrogen oxidation in that organism. Implications of these findings with respect to dihydrogen metabolism are discussed.
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Affiliation(s)
- J C Chen
- Department of Biochemistry, University of Georgia, Athens 30602
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73
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Blasco R, Castillo F. Light-dependent degradation of nitrophenols by the phototrophic bacterium Rhodobacter capsulatus E1F1. Appl Environ Microbiol 1992; 58:690-5. [PMID: 1610190 PMCID: PMC195303 DOI: 10.1128/aem.58.2.690-695.1992] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Rhodobacter capsulatus E1F1, a phototrophic purple nonsulfur bacterium capable of photoassimilating nitrate or nitrite, grew phototrophically in the presence of mono- and dinitrophenols with acetate as a carbon source, the highest growth levels being obtained under microaerobic conditions. Utilization of 2,4-dinitrophenol was strictly light dependent, was inhibited by O2 and by ammonium, and took place with the simultaneous and stoichiometric production of 2-amino-4-nitrophenol, which accumulated in the medium and was poorly used for further growth in anaerobiosis. Metabolism of mononitrophenols was also light dependent but was activated by O2 and by ammonium. Metabolism of nitrophenols seemed to depend on inducible systems which were repressed in nitrogen-starved cells. Induction of the in vivo 2,4-dinitrophenol reducing system was strongly inhibited by chloramphenicol.
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Affiliation(s)
- R Blasco
- Departamento de Bioquímica, Biología Molecular y Fisiología, Facultad de Ciencias, Universidad de Córdoba, Spain
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74
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Wright GE, Madigan MT. Photocatabolism of Aromatic Compounds by the Phototrophic Purple Bacterium
Rhodomicrobium vannielii. Appl Environ Microbiol 1991; 57:2069-73. [PMID: 16348527 PMCID: PMC183523 DOI: 10.1128/aem.57.7.2069-2073.1991] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The phototrophic purple non-sulfur bacterium
Rhodomicrobium vannielii
grew phototrophically (illuminated anaerobic conditions) on a variety of aromatic compounds (in the presence of CO
2
). Benzoate was universally photocatabolized by all five strains of
R. vannielii
examined, and benzyl alcohol was photocatabolized by four of the five strains. Catabolism of benzyl alcohol by phototrophic bacteria has not been previously reported. Other aromatic substrates supporting reasonably good growth of
R. vannielii
strains were the methoxylated benzoate derivatives vanillate (4-hydroxy-3-methoxybenzoate) and syringate (4-hydroxy-3,5-dimethoxybenzoate). However, catabolism of vanillate and syringate led to significant inhibition of bacteriochlorophyll synthesis in
R. vannielii
cells, eventually causing cultures to cease growing. No such effect on photopigment synthesis in cells grown on benzoate or benzyl alcohol was observed. Along with a handful of other species of anoxygenic phototrophic bacteria, the ability of the species
R. vannielii
to photocatabolize aromatic compounds indicates that this organism may also be ecologically significant as a consumer of aromatic derivatives in illuminated anaerobic habitats in nature.
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Affiliation(s)
- G E Wright
- Department of Microbiology, Southern Illinois University, Carbondale, Illinois 62901
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75
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Menon AL, Stults LW, Robson RL, Mortenson LE. Cloning, sequencing and characterization of the [NiFe]hydrogenase-encoding structural genes (hoxK and hoxG) from Azotobacter vinelandii. Gene 1990; 96:67-74. [PMID: 2265761 DOI: 10.1016/0378-1119(90)90342-o] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The Azotobacter vinelandii [NiFe]hydrogenase-encoding structural genes were isolated from an A. vinelandii genomic cosmid library. Nucleotide (nt) sequence analysis showed that the two genes, hoxK and hoxG, which encode the small and large subunits of the enzyme, respectively, form part of an operon that contains at least one other gene. The hoxK gene encodes a polypeptide of 358 amino acids (aa) (39,209 Da). The deduced aa sequence encodes a possible 45-aa N-terminus extension, not present in the purified A. vinelandii hydrogenase small subunit, which could be a cellular targeting sequence. The hoxG gene is downstream form, and overlaps hoxK by 4 nt and encodes a 602-aa polypeptide of 66,803 Da. The hoxK and hoxG gene products display homology to aa sequences of hydrogenase small and large subunits, respectively, from other organisms. The hoxG gene lies 16 nt upstream from a third open reading frame which could encode a 27,729-Da (240-aa) hydrophobic polypeptide containing 53% nonpolar and 11% aromatic aa. The significance of this possible third gene is not known at present.
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Affiliation(s)
- A L Menon
- Department of Biochemistry, University of Georgia, Athens 30602
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76
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77
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Hallenbeck PL, Lerchen R, Hessler P, Kaplan S. Phosphoribulokinase activity and regulation of CO2 fixation critical for photosynthetic growth of Rhodobacter sphaeroides. J Bacteriol 1990; 172:1749-61. [PMID: 2156801 PMCID: PMC208665 DOI: 10.1128/jb.172.4.1749-1761.1990] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The Rhodobacter sphaeroides genome contains two unlinked genetic regions each encoding numerous proteins involved in CO2 fixation which include phosphoribulokinases (prkA and prkB), ribulose 1,5-bisphosphate carboxylase/oxygenase (rbcLS and rbcR) (P. L. Hallenbeck and S. Kaplan, Photosynth. Res. 19:63-71, 1988; F. R. Tabita, Microbiol. Rev. 52:155-189, 1988), and two open reading frames linked to rbcLS and rbcR, namely, cfxA and cfxB, respectively (P. L. Hallenbeck, R. Lerchen, P. Hessler, and S. Kaplan, J. Bacteriol. 172:1736-1748). In this study, we examined the unique role(s) of each phosphoribulokinase activity in the regulation of CO2 fixation. Strains were constructed which contain null mutations in prkA and/or prkB. Studies utilizing these strains suggested that CO2 fixation plays an essential role in attaining the cellular redox balance necessary for photoheterotrophic growth. The presence of an external electron acceptor can negate the requirement for CO2 for photoheterotrophic growth. Each form of phosphoribulokinase and ribulose 1,5-bisphosphate carboxylase/oxygenase was shown to have distinct roles in CO2 metabolism when cells were exposed to extremes in CO2 levels. Evidence is also presented which unequivocally demonstrated that regulation of the expression of the enzymes involved in CO2 metabolism is effective at the transcriptional level. Although the two regions of the DNA involved in CO2 fixation are physically unlinked, each region of the DNA can have a profound effect on the expression of the other region of the DNA.
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Affiliation(s)
- P L Hallenbeck
- Department of Microbiology, University of Texas Medical School, Houston 77225
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78
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Hallenbeck PL, Lerchen R, Hessler P, Kaplan S. Roles of CfxA, CfxB, and external electron acceptors in regulation of ribulose 1,5-bisphosphate carboxylase/oxygenase expression in Rhodobacter sphaeroides. J Bacteriol 1990; 172:1736-48. [PMID: 2108123 PMCID: PMC208664 DOI: 10.1128/jb.172.4.1736-1748.1990] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The Rhodobacter sphaeroides genome contains two unlinked genetic regions each encoding a series of proteins involved in CO2 fixation which include phosphoribulokinase (prkA and prkB) and ribulose 1,5-bisphosphate carboxylase/oxygenase (rbcLS and rbcR) (P. L. Hallenbeck and S. Kaplan, Photosynth. Res. 19:63-71, 1988; F. R. Tabita, Microbiol. Rev. 52:155-189, 1988). We examined the effect of CO2 in the presence and absence of an alternate electron acceptor, dimethyl sulfoxide, on the expression of rbcR and rbcLS in photoheterotrophically grown R. sphaeroides. The expression of both rbcR and rbcLS was shown to depend on the CO2 concentration when succinate was used as the carbon source. It was also demonstrated that CO2 fixation is critical for photoheterotrophic growth but could be replaced by the alternative reduction of dimethyl sulfoxide to dimethyl sulfide. Dimethyl sulfoxide severely depressed both rbcR and rbcLS expression in cells grown photoheterotrophically at CO2 concentrations of 0.05% or greater. However, cells grown photoheterotrophically in the absence of exogenous CO2 but in the presence of dimethyl sulfoxide had intermediate levels of expression of rbcL and rbcR, suggesting partially independent control by limiting CO2 tension. We also present evidence for the existence of two gene products, namely, CfxA and CfxB, which are encoded by genes immediately upstream of rbcLS and rbcR, respectively. Strains were constructed which contained null mutations in cfxA and/or cfxB. Each mutation eliminated expression of the linked downstream rbc operon. Further, studies utilizing these strains demonstrated that each form of ribulose 1,5-bisphosphate carboxylase/oxygenase plays an essential role in maintaining the cellular redox balance during photoheterotrophic growth at differing CO2 concentrations.
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Affiliation(s)
- P L Hallenbeck
- Department of Microbiology, University of Texas Medical School, Houston 77225
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79
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Hamana K, Matsuzaki S, Niitsu M, Samejima K. Synthesis of novel polyamines inParacoccus, RhodobacterandMicrococcus. FEMS Microbiol Lett 1990. [DOI: 10.1111/j.1574-6968.1990.tb04031.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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80
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Wellington CL, Beatty JT. Promoter mapping and nucleotide sequence of the bchC bacteriochlorophyll biosynthesis gene from Rhodobacter capsulatus. Gene 1989; 83:251-61. [PMID: 2555268 DOI: 10.1016/0378-1119(89)90111-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Because there are not yet direct assays for most of the proteins required for differentiation of Rhodobacter capsulatus cytoplasmic membrane into photosynthetically competent intracytoplasmic membrane, a molecular inquiry into the mechanism and regulation of this process is difficult. We have, therefore, chosen to isolate R. capsulatus photosynthesis genes by creating in-frame fusions to lac'Z vectors, and selecting for those that direct appropriately regulated levels of beta-galactosidase in R. capsulatus. One lacZ fusion isolate was used to identify an open reading frame (ORF) of unknown function and flanking sequences that promoted initiation of transcription. The chromosomal copy of this ORF was mutated by insertion of a kanamycin-resistant cartridge into the cloned fragment and substitution for the chromosomal copy by homologous recombination. The phenotype of the resultant mutant cells showed that the ORF encodes 2-desacetyl-2-hydroxyethyl bacteriochlorophyllide a dehydrogenase, an enzyme that catalyzes the penultimate step in bacteriochlorophyll a biosynthesis. The nucleotide sequence of this bchC gene and its 5' regulatory region were determined. The deduced amino acid sequence shows that the bchC gene encodes a 33-kDa protein that is less hydrophobic than integral membrane proteins of R. capsulatus, although there are hydrophobic segments that could in principle interact with a lipid membrane. Results of S1 nuclease protection and primer extension experiments show that a 5' mRNA end is positioned within the cloned segment, and that this 5' end maps to sequences with significant sequence similarity to the previously characterized puf operon promoter region.
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Affiliation(s)
- C L Wellington
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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81
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Xu HW, Love J, Borghese R, Wall JD. Identification and isolation of genes essential for H2 oxidation in Rhodobacter capsulatus. J Bacteriol 1989; 171:714-21. [PMID: 2536678 PMCID: PMC209656 DOI: 10.1128/jb.171.2.714-721.1989] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Mutants of Rhodobacter capsulatus unable to grow photoautotrophically with H2 and CO2 were isolated. Those lacking uptake hydrogenase activity as measured by H2-dependent methylene blue reduction were analyzed genetically and used in complementation studies for the isolation of the wild-type genes. Results of further subcloning and transposon Tn5 mutagenesis suggest the involvement of a minimum of five genes. Hybridization to the 2.2-kilobase-pair SstI fragment that lies within the coding region for the large and small subunits of Bradyrhizobium japonicum uptake hydrogenase showed one region of strong homology among the R. capsulatus fragments isolated, which we interpret to mean that one or both structural genes were among the genes isolated.
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Affiliation(s)
- H W Xu
- Biochemistry Department, University of Missouri-Columbia 65211
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82
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Cook LS, Tabita FR. Oxygen regulation of ribulose 1,5-bisphosphate carboxylase activity in Rhodospirillum rubrum. J Bacteriol 1988; 170:5468-72. [PMID: 3142846 PMCID: PMC211639 DOI: 10.1128/jb.170.12.5468-5472.1988] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The carboxylase activity of ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBPC/O) decreased when an anaerobic culture of Rhodospirillum rubrum was exposed to atmospheric levels of oxygen. From 70 to 80% of the activity was lost within 12 to 24 h. Inactivation was apparent when the enzyme was assayed in situ (in whole cells) and when activity was measured in dialyzed crude extracts. The quantity of enzyme protein, as estimated from sodium dodecyl sulfate-polyacrylamide gels or as quantified immunologically, did not decrease within 24 h of exposure to air. Following extended exposure to aerobic conditions (48 to 72 h), degradation of enzyme occurred. These results indicate that the inactivation of RuBPC/O in R. rubrum may be due to an alteration or modification of the preformed enzyme, followed by eventual degradation of the inactive enzyme. When shifted back to anaerobic conditions (under an argon atmosphere), the RuBPC/O activity increased rapidly. This increase appeared to be due to de novo synthesis of enzyme. The increase in activity was not observed when the culture was maintained in the dark or in the absence of a suitable carbon source. Thus, the oxygen-mediated inactivation of RuBPC/O appeared to be due to some form of irreversible modification. The cloned R. rubrum RuBPC/O gene, expressed in Escherichia coli, yielded functional enzyme that was not affected by oxygen, indicating that inactivation in R. rubrum is mediated by a gene product(s) not found in E. coli.
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Affiliation(s)
- L S Cook
- Center for Applied Microbiology, University of Texas, Austin 78712-1095
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83
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Tayeh MA, Madigan MT. Malate dehydrogenases in phototrophic purple bacteria. Thermal stability, amino acid composition and immunological properties. Biochem J 1988; 252:595-600. [PMID: 3137931 PMCID: PMC1149184 DOI: 10.1042/bj2520595] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Purified malate dehydrogenases from four species of non-sulphur purple phototrophic bacteria were examined for their heat-stability, amino acid composition and antigenic relationships. Malate dehydrogenase from Rhodospirillum rubrum, Rhodobacter capsulatus and Rhodomicrobium vannielii (which are all tetrameric proteins) had an unusually high glycine content, but the enzyme from Rhodocyclus purpureus (which is a dimer) did not. R. rubrum malate dehydrogenase was extremely heat-stable relative to the other enzymes, withstanding 65 degrees C for over 1 h with no loss of activity. By contrast, malate dehydrogenase from R. vannielii lost activity above 35 degrees C, and that from R. capsulatus above 40 degrees C. Amino acid compositional relatedness and immunological studies indicated that tetrameric phototrophic-bacterial malate dehydrogenases were highly related to one another, but only distantly related to the tetrameric enzyme from Bacillus. This suggests that, despite differences in their thermal properties, the tetrameric malate dehydrogenases of non-sulphur purple bacteria constitute a distinct biochemical class of this catalyst.
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Affiliation(s)
- M A Tayeh
- Department of Microbiology, Southern Illinois University, Carbondale 62901
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84
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85
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Tucker KD, Neal JL. Growth and respiration ofBradyrhizobium japonicum USDA 143 with nitrous oxide as the terminal electron acceptor. Curr Microbiol 1988. [DOI: 10.1007/bf01568791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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86
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Amperometric method for monitoring anaerobic respiration with nitrous oxide as the terminal electron acceptor. Curr Microbiol 1988. [DOI: 10.1007/bf01568792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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87
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Hallenbeck BL, Kaplan S. Structural gene regions of Rhodobacter sphaeroides involved in CO2 fixation. PHOTOSYNTHESIS RESEARCH 1988; 19:63-71. [PMID: 24425368 DOI: 10.1007/bf00114569] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/1987] [Accepted: 02/25/1988] [Indexed: 06/03/2023]
Abstract
From studies conducted in both our laboratory and by Gibson, Tabita and colleagues, as well as drawing on the recent studies with Alcaligenes eutrophus, we describe two genetic regions which have been identified on the chromosome of Rhodobacter sphaeroides which code for a number of enzymes involved in CO2 fixation. One region was found to contain the genes coding for fructose 1,6-bisphosphatase (fbpA), phosphoribulokinase (prkA), a 37 kDa polypeptide (cfxA), and form I ribulose 1,5-bisphosphate carboxylase/oxygenase (rbcL, S). These genes appear to be expressed in the same transcriptional direction and are tandomly arranged. A second, apparently unlinked region of the chromosome contains a duplicate (with respect to functionality of gene products) but not identical set of these same four genes. Although the gene order in both regions is apparently identical, there is approximately 4 kb of DNA separating the 3'-end of prkB and the beginning of cfxB. The specific genetic organizations and proposed roles of these two genetic regions are discussed.
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Affiliation(s)
- B L Hallenbeck
- Department of Microbiology, University of Illinois, 407 South Goodwin Avenue, 61801, Urbana, IL, USA
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88
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Madigan MT, Gest H. Selective enrichment and isolation ofRhodopseudomonas palustrisusingtrans-cinnamic acid as sole carbon source. FEMS Microbiol Lett 1988. [DOI: 10.1111/j.1574-6968.1988.tb02647.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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89
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Hallenbeck PL, Kaplan S. Cloning of the gene for phosphoribulokinase activity from Rhodobacter sphaeroides and its expression in Escherichia coli. J Bacteriol 1987; 169:3669-78. [PMID: 3038847 PMCID: PMC212449 DOI: 10.1128/jb.169.8.3669-3678.1987] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
A 3.4-kilobase EcoRI restriction endonuclease fragment has been cloned from the facultatively photoheterotrophic bacterium Rhodobacter sphaeroides and shown to contain the structural gene (prkA) for phosphoribulokinase (PRK) activity. The PRK activity was characterized in Escherichia coli, and the product of the reaction was identified. The prkA gene was localized to a 1,565-base-pair EcoRI-PstI restriction endonuclease fragment and gave rise to a 33-kilodalton polypeptide both in vivo and in vitro. The gene product produced in E. coli was shown to be identical to the gene product produced in R. sphaeroides. The amino acid sequence for the amino-terminal region deduced from the DNA sequence confirmed that derived for partially purified PRK derived from both E. coli and R. sphaeroides. In addition, the 3.4-kilobase EcoRI restriction endonuclease fragment coded for a 37-kilodalton polypeptide of unknown function, and preliminary evidence indicates that this DNA fragment is linked to genes coding for other activities significant in photosynthetic carbon assimilation. The genetic organization and proposed operon structure of this DNA fragment are discussed.
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90
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Ferguson SJ, Jackson J, McEwan AG. Anaerobic respiration in the Rhodospirillaceae: characterisation of pathways and evaluation of roles in redox balancing during photosynthesis. FEMS Microbiol Lett 1987. [DOI: 10.1111/j.1574-6968.1987.tb02455.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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91
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Michalski WP, Nicholas DJD. Inhibition of nitrogenase by nitrite and nitric oxide in Rhodopseudomonas sphaeroides f. sp. denitrificans. Arch Microbiol 1987. [DOI: 10.1007/bf00463493] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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92
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93
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Richardson DJ, Kelly DJ, Jackson JB, Ferguson SJ, Alef K. Inhibitory effects of myxothiazol and 2-n-heptyl-4-hydroxyquinoline-N-oxide on the auxiliary electron transport pathways of Rhodobacter capsulatus. Arch Microbiol 1986. [DOI: 10.1007/bf00402344] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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94
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95
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McEwan AG, Greenfield AJ, Wetzstein HG, Jackson JB, Ferguson SJ. Nitrous oxide reduction by members of the family Rhodospirillaceae and the nitrous oxide reductase of Rhodopseudomonas capsulata. J Bacteriol 1985; 164:823-30. [PMID: 2997133 PMCID: PMC214325 DOI: 10.1128/jb.164.2.823-830.1985] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
After growth in the absence of nitrogenous oxides under anaerobic phototrophic conditions, several strains of Rhodopseudomonas capsulata were shown to possess a nitrous oxide reductase activity. The enzyme responsible for this activity had a periplasmic location and resembled a nitrous oxide reductase purified from Pseudomonas perfectomarinus. Electron flow to nitrous oxide reductase was coupled to generation of a membrane potential and inhibited by rotenone but not antimycin. It is suggested that electron flow to nitrous oxide reductase branches at the level of ubiquinone from the previously characterized electron transfer components of R. capsulata. This pathway of electron transport could include cytochrome c', a component hitherto without a recognized function. R. capsulata grew under dark anaerobic conditions in the presence of malate as carbon source and nitrous oxide as electron acceptor. This confirms that nitrous oxide respiration is linked to ATP synthesis. Phototrophically and anaerobically grown cultures of nondenitrifying strains of Rhodopseudomonas sphaeroides, Rhodopseudomonas palustris, and Rhodospirillum rubrum also possessed nitrous oxide reductase activity.
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96
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Vignais PM, Colbeau A, Willison JC, Jouanneau Y. Hydrogenase, nitrogenase, and hydrogen metabolism in the photosynthetic bacteria. Adv Microb Physiol 1985; 26:155-234. [PMID: 3913292 DOI: 10.1016/s0065-2911(08)60397-5] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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97
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Quivey RG, Tabita FR. Cloning and expression in Escherichia coli of the form II ribulose 1,5-bisphosphate carboxylase/oxygenase gene from Rhodopseudomonas sphaeroides. Gene 1984; 31:91-101. [PMID: 6396166 DOI: 10.1016/0378-1119(84)90198-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The gene encoding the form II ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBPC/O) from Rhodopseudomonas (R.) sphaeroides has been identified on a 3-kb EcoRI fragment and cloned into a broad-host-range, high-copy-number plasmid, using the gene from Rhodospirillum (Rs.) rubrum as a hybridization probe. Subclones of the gene from R. sphaeroides in pBR322 and pUC8 show substantial levels of expression and enzymatic activity in whole cells and crude cell extracts of Escherichia coli. This enzymatic activity has been shown to be similar in many respects to that of the protein purified from R. sphaeroides.
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98
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Abstract
A thermophilic photosynthetic purple bacterium was isolated from the waters of a hot spring in Yellowstone National Park, Wyoming. The organism differs from all known purple bacteria in that it grows optimally at a temperature of about 50 degrees C. The isolate contains bacteriochlorophyll a and grows autotrophically, oxidizing sulfide to elemental sulfur which is then stored as globules inside the cell. These properties indicate that the phototroph is a member of the Chromatiaceae (purple sulfur bacteria).
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99
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Spear N, Sojka GA. Conversion of two distinctRhodopseudomonas capsulataisolates to the glycerol-utilizing phenotype. FEMS Microbiol Lett 1984. [DOI: 10.1111/j.1574-6968.1984.tb00738.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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100
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Willison JC, Madern D, Vignais PM. Increased photoproduction of hydrogen by non-autotrophic mutants of Rhodopseudomonas capsulata. Biochem J 1984; 219:593-600. [PMID: 6146310 PMCID: PMC1153517 DOI: 10.1042/bj2190593] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Non-autotrophic ( Aut -) mutants of Rhodopseudomonas capsulata B10 were tested for their efficiency of nitrogenase-mediated H2 production. Three of these mutants ( IR3 , IR4 and IR5 ) showed an increase stoichiometry of H2 production, mediated by nitrogenase, from certain organic substrates. For example, in a medium containing 7 mM-L-glutamate as nitrogen source, strain IR4 produced 10-20% more H2 than did the wild type with DL-lactate or L-malate as major carbon source, 20-50% more H2 with DL-malate, and up to 70% more with D-malate. Strain IR4 was deficient in 'uptake' hydrogenase activity as measured by H2-dependent reduction of Methylene Blue or Benzyl Viologen. However, this observation did not explain the increased efficiency of H2 production, since H2 uptake (H2 recycling) was undetectable in cells of the wild type. Instead, increased H2 production by the mutant appeared to be due to an improved conversion of organic substrates to H2 and CO2, presumably due to an altered carbon metabolism. The metabolism of D-malate by different strains was studied. An NAD+-dependent D-malic enzyme was synthesized constitutively by the wild type, and showed a Km for D-malate of 3 mM. The activity of this enzyme was approx. 50% higher in strain IR4 than in the wild type, and the mutant also grew twice as fast as the wild type with D-malate as sole carbon source.
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