Synthesis of the Succinic Ester of Homoserine, a New Intermediate in the Bacterial Biosynthesis of Methionine<sup>*</sup>

Flavin, Martin; Slaughter, Clarence

doi:10.1021/bi00883a022

Cited by 84 publications

(30 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2A), as confirmed by comparison with spectra of authentic standards (data not shown). NAS originates from OAS by a known spontaneous intramolecular shift of the acetyl moiety from the hydroxyl to the amino group (25). Labeled OAS and NAS were undetectable in the spectra recorded from suspensions of serat2;2 mitochondria (Fig.…”

Section: Mitochondrial Synthesis and Export Of Oas-the Metabolism Of [3-mentioning

confidence: 93%

Mitochondrial Cysteine Synthase Complex Regulates O-Acetylserine Biosynthesis in Plants

Wirtz

Beard

Lee

et al. 2012

Journal of Biological Chemistry

View full text Add to dashboard Cite

Background: Cysteine biosynthesis is the exclusive entry point for reduced sulfur in cellular metabolism. Results: The mitochondrial cysteine synthase complex (mCSC) regulates serine acetyltransferase activity in response to cysteine availability. Conclusion:The mCSC is a sensor of sulfur availability and regulates cysteine synthesis. Significance: The integration of cysteine in the regulatory model of the CSC establishes a new sensory function for the mCSC.

show abstract

Section: Mitochondrial Synthesis and Export Of Oas-the Metabolism Of [3-mentioning

confidence: 93%

Mitochondrial Cysteine Synthase Complex Regulates O-Acetylserine Biosynthesis in Plants

Wirtz

Beard

Lee

et al. 2012

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…OAS is a labile compound that spontaneously converts into N-acetylserine in a pH-dependent manner. The conversion rate is 1% min -1 at pH 7.6 (Flavin and Slaughter, 1965). N-acetylserine has no known function in plant metabolism, but is the inducer of the cysteine regulon in bacteria (Kredich, 1996).…”

Section: Pathways Leading To Cysteine: Step 1 -Synthesis Of Oas By Sementioning

confidence: 99%

Molecular Biology, Biochemistry and Cellular Physiology of Cysteine Metabolism inArabidopsis thaliana

Hell

Wirtz

2011

The Arabidopsis Book

109

View full text Add to dashboard Cite

Cysteine is one of the most versatile molecules in biology, taking over such different functions as catalysis, structure, regulation and electron transport during evolution. Research on Arabidopsis has contributed decisively to the understanding of cysteine synthesis and its role in the assimilatory pathways of S, N and C in plants. The multimeric cysteine synthase complex is present in the cytosol, plastids and mitochondria and forms the centre of a unique metabolic sensing and signaling system. Its association is reversible, rendering the first enzyme of cysteine synthesis active and the second one inactive, and vice-versa. Complex formation is triggered by the reaction intermediates of cysteine synthesis in response to supply and demand and gives rise to regulation of genes of sulfur metabolism to adjust cellular sulfur homeostasis. Combinations of biochemistry, forward and reverse genetics, structural-and cell-biology approaches using Arabidopsis have revealed new enzyme functions and the unique pattern of spatial distribution of cysteine metabolism in plant cells. These findings place the synthesis of cysteine in the centre of the network of primary metabolism.

show abstract

“…This reaction is known to occur spontaneously by means of an intramolecular 0-to-N acetyl shift with a first-order rate constant of 0.98% per min at pH 7.5 and 29°C (13). This constant is directly proportional to the concentration of nonprotonated amino group, viz., NH2, and therefore is larger at higher pHs.…”

Section: *7mentioning

confidence: 99%

Molecular characterization of the cysJIH promoters of Salmonella typhimurium and Escherichia coli: regulation by cysB protein and N-acetyl-L-serine

1989

View full text Add to dashboard Cite

The cysJIH promoter regions from Salmonella typhimurium LT7 and Escherichia coli B were cloned and sequenced. Primer extension analyses showed that the major in vivo transcription initiation site in S. typhimurium is located 171 nucleotides upstream of the cysJ start codon. Minor start sites were found 8 and 9 nucleotides downstream of the major site. In vivo transcription initiation in E. coli was found to occur at a single site 66 nucleotides upstream of the cysJ start codon. Primer extension studies also indicated that chromosomal cysJIH transcription is stimulated by sulfur limitation and repressed by growth on L-cystine. Paradoxically, in strains carrying plasmids containing the S. typhimurium cysJIH region, the highest levels of primer extension products were found with RNA from cells grown on L-cystine, even though levels of the proteins encoded by cysJ and cysl were normally repressed. In vitro transcription runoff studies with DNA template from the S. typhimurium cysJIH promoter region showed synthesis of a product originating at the major in vivo start site, which was dependent on the presence of purified cysB protein and either O-acetyl-L-serine or N-acetyl-L-serine. N-Acetyl-L-serine was 10-to 30-fold more active than O-acetyl-L-serine as an in vitro inducer of cysJIH transcription.Synthesis of L-cysteine by Salmonella typhimurium and Escherichia coli involves cellular uptake and reduction of sulfate to sulfide, the synthesis of O-acetyl-L-serine from L-serine and acetyl coenzyme A by serine transacetylase, and the reaction of O-acetyl-L-serine with sulfide in a reaction catalyzed by O-acetylserine (thiol)-lyase (reviewed in reference 20). Except for serine transacetylase, these biosynthetic activities are regulated at the gene level as a system of positive control termed the cysteine regulon, wherein gene expression requires sulfur limitation and the cysB regulatory protein (17, 19), a tetramer of identical 36-kilodalton subunits (27,35). Serine transacetylase is controlled through feedback inhibition by L-cysteine (21,22). In addition to acting as an L-cysteine precursor, 0-acetyl-L-serine is considered an internal inducer of the cysteine regulon because cysE strains (lacking serine transacetylase) cannot be derepressed by sulfur limitation unless provided with an external source of 0-acetyl-L-serine (18,19).Known genes of the cysteine regulon are widely scattered on the chromosome in five different clusters (2, 40). The cysJIH region consists of contiguous genes specifying the flavoprotein (cysJ) and hemoprotein (cysI) components of NADPH-sulfite reductase (42, 44) and for 3'-phosphoadenosine 5'-phosphosulfate sulfotransferase (cysH) (11). Regulation of cysJIH is at the level of transcription (12), and genetic studies indicate that these three genes constitute a single transcriptional unit with the order promoter-cysJ-cysl-cysH (9,24,34 here in vivo and in vitro studies that characterize the cysJIH promoter and show that its activity is dependent on cysB protein and either O-acetyl-L-serine or ...

show abstract

Synthesis of the Succinic Ester of Homoserine, a New Intermediate in the Bacterial Biosynthesis of Methionine^*

Cited by 84 publications

References 13 publications

Mitochondrial Cysteine Synthase Complex Regulates O-Acetylserine Biosynthesis in Plants

Mitochondrial Cysteine Synthase Complex Regulates O-Acetylserine Biosynthesis in Plants

Molecular Biology, Biochemistry and Cellular Physiology of Cysteine Metabolism inArabidopsis thaliana

Molecular characterization of the cysJIH promoters of Salmonella typhimurium and Escherichia coli: regulation by cysB protein and N-acetyl-L-serine

Contact Info

Product

Resources

About

Synthesis of the Succinic Ester of Homoserine, a New Intermediate in the Bacterial Biosynthesis of Methionine*

Cited by 84 publications

References 13 publications

Mitochondrial Cysteine Synthase Complex Regulates O-Acetylserine Biosynthesis in Plants

Mitochondrial Cysteine Synthase Complex Regulates O-Acetylserine Biosynthesis in Plants

Molecular Biology, Biochemistry and Cellular Physiology of Cysteine Metabolism inArabidopsis thaliana

Molecular characterization of the cysJIH promoters of Salmonella typhimurium and Escherichia coli: regulation by cysB protein and N-acetyl-L-serine

Contact Info

Product

Resources

About

Synthesis of the Succinic Ester of Homoserine, a New Intermediate in the Bacterial Biosynthesis of Methionine^*