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Jaschke PR, Hardjasa A, Digby EL, Hunter CN, Beatty JT. A BchD (magnesium chelatase) mutant of rhodobacter sphaeroides synthesizes zinc bacteriochlorophyll through novel zinc-containing intermediates. J Biol Chem 2011; 286:20313-22. [PMID: 21502322 PMCID: PMC3121458 DOI: 10.1074/jbc.m110.212605] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Heme and bacteriochlorophyll a (BChl) biosyntheses share the same pathway to protoporphyrin IX, which then branches as follows. Fe(2+) chelation into the macrocycle by ferrochelatase results in heme formation, and Mg(2+) addition by Mg-chelatase commits the porphyrin to BChl synthesis. It was recently discovered that a bchD (Mg-chelatase) mutant of Rhodobacter sphaeroides produces an alternative BChl in which Mg(2+) is substituted by Zn(2+). Zn-BChl has been found in only one other organism before, the acidophilic Acidiphilium rubrum. Our objectives in this work on the bchD mutant were to 1) elucidate the Zn-BChl biosynthetic pathway in this organism and 2) understand causes for the low amounts of Zn-BChl produced. The bchD mutant was found to contain a Zn-protoporphyrin IX pool, analogous to the Mg-protoporphyrin IX pool found in the wild type strain. Inhibition of ferrochelatase with N-methylprotoporphyrin IX caused Zn-protoporphyrin IX and Zn-BChl levels to decline by 80-90% in the bchD mutant, whereas in the wild type strain, Mg-protoporphyrin IX and Mg-BChl levels increased by 170-240%. Two early metabolites of the Zn-BChl pathway were isolated from the bchD mutant and identified as Zn-protoporphyrin IX monomethyl ester and divinyl-Zn-protochlorophyllide. Our data support a model in which ferrochelatase synthesizes Zn-protoporphyrin IX, and this metabolite is acted on by enzymes of the BChl pathway to produce Zn-BChl. Finally, the low amounts of Zn-BChl in the bchD mutant may be due, at least in part, to a bottleneck upstream of the step where divinyl-Zn-protochlorophyllide is converted to monovinyl-Zn-protochlorophyllide.
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Affiliation(s)
- Paul R. Jaschke
- From the Department of Microbiology and Immunology, University of British Columbia, Vancouver V6T 1Z3, British Columbia, Canada and
| | - Amelia Hardjasa
- From the Department of Microbiology and Immunology, University of British Columbia, Vancouver V6T 1Z3, British Columbia, Canada and
| | - Elizabeth L. Digby
- From the Department of Microbiology and Immunology, University of British Columbia, Vancouver V6T 1Z3, British Columbia, Canada and
| | - C. Neil Hunter
- the Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - J. Thomas Beatty
- From the Department of Microbiology and Immunology, University of British Columbia, Vancouver V6T 1Z3, British Columbia, Canada and , To whom correspondence should be addressed: Dept. of Microbiology and Immunology, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada. Fax: 604-822-6041; E-mail:
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Granick S, Beale SI. Hemes, chlorophylls, and related compounds: biosynthesis and metabolic regulation. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 46:33-203. [PMID: 345768 DOI: 10.1002/9780470122914.ch2] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Terada LS, Piermattei D, Shibao GN, McManaman JL, Wright RM. Hypoxia regulates xanthine dehydrogenase activity at pre- and posttranslational levels. Arch Biochem Biophys 1997; 348:163-8. [PMID: 9390187 DOI: 10.1006/abbi.1997.0367] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hypoxia increases the activity of xanthine oxidase (XO) and its precursor, xanthine dehydrogenase (XDH), but the mechanism of regulation is unclear. In hypoxic Swiss 3T3 cells, an early (0-24 h) cycloheximide-insensitive increase in XO-XDH activity, coupled with a lack of increase in de novo XO-XDH synthesis (immunoprecipitation) or mRNA levels (quantitative RT-PCR), demonstrated a posttranslational effect of hypoxia. Similarly, hyperoxia decreased XO-XDH activity faster than could be accounted for by cessation of XO-XDH protein synthesis. In further support of a posttranslational effect, cells transfected with a constitutively driven XDH construct displayed an exaggerated increase in activity in hypoxia but no increase in activity in hyperoxia. However, more prolonged exposure to hypoxia (24-48 h) induced an increase in XO-XDH mRNA levels and de novo XO-XDH protein synthesis, suggesting an additional pretranslational effect. Finally, hypoxic induction of XO-XDH activity was found to be cell-type-restricted. We conclude that control of XO-XDH levels by oxygen tension is a complex process which involves several points of regulation.
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Affiliation(s)
- L S Terada
- Webb-Waring Institute for Biomedical Research, University of Colorado Health Sciences Center, Denver 80262, USA.
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Abstract
5-Aminolevulinic acid (ALA), a universal precursor of tetrapyrrole compounds can be synthesized by two pathways: the C5 (glutamate) pathway and ALA synthase. From the phylogenetic distribution it is shown that distribution of ALA synthase is restricted to the alpha subclass of purple bacteria in prokaryotes, and further distributed to mitochondria of eukaryotes. The monophyletic origin of bacterial and eukaryotic ALA synthase is shown by sequence analysis of the enzyme. Evolution of ALA synthase in the alpha subclass of purple bacteria is discussed in relation to the energy-generating and biosynthetic devices in subclasses of this bacteria.
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Affiliation(s)
- T Oh-hama
- Research Institute of Evolutionary Biology, Tokyo, Japan
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Zeilstra-Ryalls JH, Kaplan S. Regulation of 5-aminolevulinic acid synthesis in Rhodobacter sphaeroides 2.4.1: the genetic basis of mutant H-5 auxotrophy. J Bacteriol 1995; 177:2760-8. [PMID: 7751286 PMCID: PMC176947 DOI: 10.1128/jb.177.10.2760-2768.1995] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Rhodobacter sphaeroides H-5 was isolated as a 5-aminolevulinic acid (ALA) auxotroph following treatment of wild-type cells with N-methyl-N-nitroso-N'-nitroguanidine (J. Lascelles and T. Altshuler, J. Bacteriol. 98:721-727, 1969). The existence in R. sphaeroides 2.4.1 of the genes hemA and hemT, each encoding the enzyme 5-aminolevulinic acid synthase (EC 2.3.1.37), raised questions as to the genetic basis for the ALA auxotrophy in mutant H-5. We therefore cloned both the hemA and hemT genes from mutant H-5. The hemA gene has been sequenced in its entirety and bears four base pair substitutions which encode three amino acid changes relative to the sequence of wild-type strain 2.4.1. Complementation analysis of an Escherichia coli ALA auxotroph has revealed that the loss of ALA synthase activity in the HemA mutant enzyme could be localized to two of the amino acid substitutions. On the other hand, the hemT gene from mutant H-5 was able to complement an E. coli mutant requiring ALA for growth. Complementation analyses were also carried out by introducing the cloned hemA or hemT gene of mutant H-5 or wild-type 2.4.1 in trans into H-5 and, in parallel, into our previously described HemA-HemT double mutant strain AT1 (E. L. Neidle and S. Kaplan, J. Bacteriol. 175:2304-2313, 1993). This analysis revealed that while the complementation pattern of mutant AT1 parallels that for the E. coli ALA auxotroph, mutant H-5 could only be complemented by the wild-type hemA gene. The ability of the hemT gene of either mutant H-5 or wild-type 2.4.1 to complement the ALA auxotrophy of mutant AT1 but not mutant H-5 was consistent with beta-galactosidase activities obtained with hemT-lacZ transcriptional fusions. We conclude that the ALA auxotrophy of mutant H-5 arises from (i) a nonfunctional HemA protein containing multiple missense substitutions and (ii) an inability of the normal hemT gene to be expressed in the mutant H-5 genetic background, i.e., an additional mutation of unknown origin is required for hemT expression. These studies bear directly on the regulation of the expression of the hemA and hemT genes of R. sphaeroides 2.4.1.
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Affiliation(s)
- J H Zeilstra-Ryalls
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston 77225, USA
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Sasikala C, Ramana CV. Biotechnological potentials of anoxygenic phototrophic bacteria. I. Production of single-cell protein, vitamins, ubiquinones, hormones, and enzymes and use in waste treatment. ADVANCES IN APPLIED MICROBIOLOGY 1995; 41:173-226. [PMID: 7572333 DOI: 10.1016/s0065-2164(08)70310-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- C Sasikala
- Department of Botany, Osmania University, Hyderabad, India
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Coomber SA, Jones RM, Jordan PM, Hunter CN. A putative anaerobic coproporphyrinogen III oxidase in Rhodobacter sphaeroides. I. Molecular cloning, transposon mutagenesis and sequence analysis of the gene. Mol Microbiol 1992; 6:3159-69. [PMID: 1333567 DOI: 10.1111/j.1365-2958.1992.tb01772.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A mutant of Rhodobacter sphaeroides, N1, has been isolated which is incapable of photosynthetic growth and, instead of synthesizing bacteriochlorophyll, N1 excretes coproporphyrin III into the growth medium. Using conjugative gene transfer, several clones were isolated from a R. sphaeroides gene library which restored normal pigment synthesis and photosynthetic growth to N1. Using transposon Tn5 mutagenesis, the gene was located to a 1.05 kb EcoRI fragment. Sequence and transcription analysis defined the position and expression of an open reading frame of approximately 920 bp, which is proposed as the anaerobic coproporphyrinogen III oxidase dedicated to bacteriochlorophyll biosynthesis.
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Affiliation(s)
- S A Coomber
- School of Biological Sciences, Queen Mary and Westfield College, University of London, UK
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Chapter 7 The genes of tetrapyrrole biosynthesis. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/s0167-7306(08)60114-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Tai TN, Moore MD, Kaplan S. Cloning and characterization of the 5-aminolevulinate synthase gene(s) from Rhodobacter sphaeroides. Gene 1988; 70:139-51. [PMID: 3266489 DOI: 10.1016/0378-1119(88)90112-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The 5-aminolevulinate synthase gene (hemA) from Rhizobium meliloti was used to probe a genomic lambda bank derived from Rhodobacter sphaeroides DNA. Two phage clones were found to bear homology to the Rhizobium probe. Southern hybridization analysis of the two lambda phage clones, which we designated lambda Hem 10 and lambda Hem 12, showed that the homology to the Rhizobium hemA gene was localized to a 3.1-kb SalI fragment derived from lambda Hem 10 and a 7.0-kb SalI fragment derived from lambda Hem 12. Each of the SalI fragments was subsequently cloned into the multiple cloning site of pUC19 in both orientations relative to the lac promoter. Restriction analysis confirmed that each SalI fragment was unique. It was also shown from Southern hybridization analysis that the regions of homology within each of the R. sphaeroides restriction fragments and the Rhizobium probe were different. Further, we have tentatively concluded that each R. sphaeroides hemA gene shows a relatively low degree of homology to the other. Data obtained from in vitro transcription-translation studies in a homologous R. sphaeroides cell-free system, and complementation of hemA mutations of both Escherichia coli and R. sphaeroides by either of the putative hemA clones suggested the presence of a gene encoding 5-aminolevulinate synthase on each DNA sequence. The fact that 5-aminolevulinate synthase activity could be demonstrated in mutant strains complemented in trans with either cloned DNA fragment further supported this conclusion.
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Affiliation(s)
- T N Tai
- Department of Microbiology, University of Illinois, Urbana-Champaign 61801
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Stimulation of vitamin B12 formation in aerobically-grownRhodopseudomonas gelatinosa under microaerobic condition. Biotechnol Lett 1986. [DOI: 10.1007/bf01025207] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Clement-Metral JD, Fanica-Gaignier F. 5-Aminolevulinic-acid synthetases from Rhodopseudomonas spheroides Y. Comparison of the purification and properties of enzymes extracted from bacteria grown in different iron concentrations. EUROPEAN JOURNAL OF BIOCHEMISTRY 1975; 59:73-7. [PMID: 1081946 DOI: 10.1111/j.1432-1033.1975.tb02426.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The two 5-aminolevulinic acid synthetases of Rhodopseudomonas spheroides Y. were extracted from cells grown in a 'low-iron' medium and purified. They have a specific activity 10-fold higher than the 'high-iron' enzymes described by us previously and have the same properties except that they do not contain any iron and have one free-SH group more per mole of enzyme (2 for E1; , for E2) Their inhibition by adenosine triphosphate and iron and their oxidation-reduction sensitivity are discussed in terms of light, oxygen and heme feed-back regulation of bacteriochlorophyll sunthesis.
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Fanica-Gaignier M, Clément-Métral J. Cellular compartmentation of two species of delta-aminolevulinic acid synthetase in a facultative photohetero-trophic bacterium (Rps. spheroides Y.). Biochem Biophys Res Commun 1973; 55:610-5. [PMID: 4543401 DOI: 10.1016/0006-291x(73)91187-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Zaman Z, Jordan PM, Akhtar M. Mechanism and stereochemistry of the 5-aminolaevulinate synthetase reaction. Biochem J 1973; 135:257-63. [PMID: 4543543 PMCID: PMC1165818 DOI: 10.1042/bj1350257] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
1. Two mechanisms for the biosynthesis of 5-aminolaevulinate from glycine and succinyl-CoA (3-carboxypropionyl-CoA) are considered. One of the mechanisms involves the retention of both the C-2 H atoms of glycine during the synthesis of 5-aminolaevulinate, whereas the other predicts the retention of only one of the C-2 H atoms of glycine. 2. Highly purified 5-aminolaevulinate synthetase from Rhodopseudomonas spheroides was used to show that the C-2 H atom of glycine with R configuration is specifically removed during the biosynthesis of 5-aminolaevulinate. 3. The mechanism of the condensation therefore differs from the analogous reaction of the biosynthesis of sphinganine from palmitoyl-CoA and serine, in which the C-2 H of serine is retained (Wiess, 1963).
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Tuboi S, Hayasaka S. Control of -aminolevulinate synthetase activity in Rhodopseudomonas spheroides. II. Requirement of a disulfide compound for the conversion of the inactive form of fraction I to the active form. Arch Biochem Biophys 1972; 150:690-7. [PMID: 4537847 DOI: 10.1016/0003-9861(72)90087-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Tuboi S, Hayasaka S. Control of -aminolevulinate synthetase activity in Rhodopseudomonas spheroides. I. Partial purification of the inactive form of fraction I. Arch Biochem Biophys 1971; 146:282-90. [PMID: 5316919 DOI: 10.1016/s0003-9861(71)80065-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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