The control of sulphate reduction in <i>Escherichia coli</i> by <i>O</i>-acetyl-<scp>l</scp>-serine

Jones‐Mortimer, M. C.; Wheldrake, J.F.; Pasternak, C. A.

doi:10.1042/bj1070051

Cited by 65 publications

(41 citation statements)

References 17 publications

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“…The sequence of genes in our cloned sequence is then nirB-nirC-cysG-ORF-3-ORF-4. The genetic organization of this region suggests that nirC may be coexpressed with cysG rather than with nirB, since nirB is followed by a structure that appears to be a rho-independent terminator, and nirC and cysG are separated by only 11 (13,30,40).…”

Section: Resultsmentioning

confidence: 99%

“…The cysJIH operon is part of the positively regulated cysteine regulon (15) and requires sulfur limitation, CysB protein, and either O-acetyl-L-serine or N-acetyl-L-serine for expression (10,11,14,28). SiR activity is also dependent on cysG, which encodes a uroporphyrinogen III methyltransferase necessary for the synthesis of siroheme (42).…”

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confidence: 99%

“…These genes are contiguous and together with cysH, the gene for 3'-phosphoadenosine 5'-phosphosulfate sulfotransferase, comprise an operon with the gene order promoter-cysJ-cysI-cysH (7,17,(26)(27)(28)(29). The cysJIH operon is part of the positively regulated cysteine regulon (15) and requires sulfur limitation, CysB protein, and either O-acetyl-L-serine or N-acetyl-L-serine for expression (10,11,14,28). SiR activity is also dependent on cysG, which encodes a uroporphyrinogen III methyltransferase necessary for the synthesis of siroheme (42).…”

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High-level expression of Escherichia coli NADPH-sulfite reductase: requirement for a cloned cysG plasmid to overcome limiting siroheme cofactor

Siegel

Kredich

1991

J Bacteriol

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The flavoprotein and hemoprotein components of Escherichia coli B NADPH-sulfite reductase are encoded by cysJ and cysl, respectively. Plasmids containing these two genes overexpressed flavoprotein catalytic activity and apohemoprotein by 13-to 35-fold, but NADPH-sulfite reductase holoenzyme activity was increased only 3-fold. Maximum overexpression of holoenzyme activity was achieved by the inclusion in such plasmids of Salmonella typhimurium cysG, which encodes a uroporphyrinogen III methyltransferase required for the synthesis of siroheme, a cofactor for the hemoprotein. Thus, cofactor deficiency, in this case siroheme, can limit overexpression of a cloned enzyme. Catalytically active holoenzyme accounted for 10% of total soluble protein in a host containing cloned cysJ, cysI, and cysG. A 5.3-kb DNA fragment containing S. typhimurium cysG was sequenced, and the open reading frame corresponding to cysG was identified by subcloning and by identifying plasmid-encoded peptides in maxicells. Comparison with the sequence reported for the E. coli cysG region (J. A. Cole, unpublished data; GenBank sequence ECONIRBC) indicates a gene order of nirB-nirC-cysG in the cloned S. typhimurium fragment. In addition, two open reading frames of unknown identity were found immediately downstream of cysG. One of these contains 11 direct repeats of 33 nucleotides each, which correspond to the consensus amino acid sequence Asp-Asp-Val-Thr-Pro-Pro-Asp-Asp-Ser-Gly-Asp.NADPH-sulfite reductase (SiR) of Escherichia coli and Salmonella typhimurium catalyzes the reduction of sulfite to sulfide and is required for synthesis of L-cysteine from inorganic sulfate (8,14). The native enzyme has a subunit structure a8,4, where a8 is a flavoprotein (SiR-FP) containing both flavin adenine dinucleotide and flavin mononucleotide and P is a hemoprotein (SiR-HP) containing an Fe4S4 center and a single molecule of siroheme (24,25,37,39). Electron flow between these cofactors proceeds from NADPH to flavin adenine dinucleotide to flavin mononucleotide in the flavoprotein, then to a closely coupled Fe4S4-siroheme center in the hemoprotein, and finally from siroheme to sulfite (38).The SiR-FP and SiR-HP components of SiR are encoded by cysJ and cysl, respectively. These genes are contiguous and together with cysH, the gene for 3'-phosphoadenosine 5'-phosphosulfate sulfotransferase, comprise an operon with the gene order promoter-cysJ-cysI-cysH (7,17,(26)(27)(28)(29). The cysJIH operon is part of the positively regulated cysteine regulon (15) and requires sulfur limitation, CysB protein, and either O-acetyl-L-serine or N-acetyl-L-serine for expression (10,11,14,28). SiR activity is also dependent on cysG, which encodes a uroporphyrinogen III methyltransferase necessary for the synthesis of siroheme (42). This gene is located more than 10 min away from cysJIH on the chromosomal map (34) and is not tightly regulated as part of the cysteine regulon (27,28). In E. coli, cysG is closely linked to nirB, the gene for another siroheme-containing enzyme, nitrite redu...

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Section: Resultsmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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High-level expression of Escherichia coli NADPH-sulfite reductase: requirement for a cloned cysG plasmid to overcome limiting siroheme cofactor

Siegel

Kredich

1991

J Bacteriol

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“…In Escherichia coli K I 2 and Salmonella typhimurium the cysteine biosynthetic pathway consists of two converging branches, the final step of which involves the reaction of 0-acetyl-L-serine and sulphide to give L-cysteine (Jones-Mortimer, Wheldrake & Pasternak, 1968;Kredich & Tomkins, 1966). On the sulphur branch, sulphate is activated via adenosine 5'-phosphosulphate to form 3'-phosphoadenosine 5'-phosphosulphate which is reduced to sulphite and then to sulphide (Dreyfuss & Monty, 1963;Pasternak et al, 1965).…”

Section: Introductionmentioning

confidence: 99%

Isolation and Characterization of cysK Mutants of Escherichia coli K12

Fimmel

Loughlin

1977

Journal of General Microbiology

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cysK mutants, deficient in 0-acetylserine sulphydrylase A [O-acetyl-L-serine acetate-lyase (adding hydrogen-sulphide); EC 4.2. gg .8], were isolated as strains resistant to selenite or giving a black colour reaction on bismuth citrate indicator medium. All were resistant to the inhibitor I ,2,4-triazole. Four independent mutants were found which possessed lowered levels of 0-acetylserine sulphydrylase activity and also partially constitutive levels of NADPH-sulphite reductase [hydrogen-sulphide : NADP+ oxidoreductase; EC I .8. I .2]. Strains containing both a cysE mutation and a cysK mutation lacked the constitutive levels of NADPH-sulphite reductase showing that these levels were due to the in vivo concentration of the inducer, 0-acetylserine. The cysK locus was found to be 81 % cotransducible with the ptsI gene.

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“…In E. coli and S. typhimurium, the synthesis of proteins involved in sulfur acquisition and utilization is triggered by the accumulation of Oacetyl-L-serine, the immediate precursor of cysteine (Jones-Mortimer et al, 1968;Kredich, 1971). In K. aerogenes, transcription of ars is inhibited by sulfate or cysteine (Adachi et al, 1974;Murooka et al, 1990;Azakami et al, 1992).…”

Section: Introductionmentioning

confidence: 99%

Mutants of Chlamydomonas with Aberrant Responses to Sulfur Deprivation.

1994

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In the absence of sulfur, Chlamydomonas reinhardtii, a unicellular green alga, lncreases its rate of sulfate import and synthesizes several periplasmic proteins, including an arylsulfatase (Ars). These changes appear to help cells acclimate to a sulfur-deficient envlronment. The elevated rate of sulfate import results from an increase in the capacity and affinity of the transport system for sulfate. The synthesis of Ars, a periplasmic enzyme that cleaves sulfate from aromatic compounds, enables cells to use these molecules as a source of sulfur when free sulfate is not available. To characterize the ways in which C. reinhardtii perceives changes in the sulfur status of the environment and regulates its responses to these changes, we mutagenized cells and isolated strains exhibiting aberrant accumulation of Ars activity. These mutants were characterized for Ars activity, ars mRNA accumulation, periplasmic protein accumulation, and sulfate transport activity when grown in both sulfur-sufficient and sulfur-deflcient conditions. All of the mutants exhlbited pleiotropic effects with respect to several of these responses. Strains harboring double mutant combinatlons were constructed and characterized for Ars activity and ars mRNA accumulation. From the mutant phenotypes, we inferred that both positlve and negative regulatory elements were involved in the acclimation process. Both the epistatic relationships among the mutations and the effects of the lesions on the responses of C. reinhardtii to sulfur limltation distinguished these mutants from similar mutants in Neurospora crassa.

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The control of sulphate reduction in Escherichia coli by O-acetyl-l-serine

Cited by 65 publications

References 17 publications

High-level expression of Escherichia coli NADPH-sulfite reductase: requirement for a cloned cysG plasmid to overcome limiting siroheme cofactor

High-level expression of Escherichia coli NADPH-sulfite reductase: requirement for a cloned cysG plasmid to overcome limiting siroheme cofactor

Isolation and Characterization of cysK Mutants of Escherichia coli K12

Mutants of Chlamydomonas with Aberrant Responses to Sulfur Deprivation.

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