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Mino, Koshiki; Yamanoue, Tsuyoshi; Ohno, Katsuhiro; Sakiyama, Takaharu; Eisaki, Naoki; Matsuyama, Asahi; Nakanishi, Koji

doi:10.1023/a:1013799915951

Cited by 15 publications

(30 citation statements)

References 8 publications

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“…In plants, CS formation relieves the intramolecular inhibition exerted by the SAT C-terminal sequence on its own activity and results in an increase of k cat /K m for acetyl-CoA (15). We cannot observe the same effect on H. influenzae SAT, in agreement with data in E. coli (35), and therefore, a different mechanism for complex regulation by effectors seems to be present in bacteria and plants. In plants, the release of the competitive intrasteric inhibition on SAT in the presence of OASS on the acetyl-CoA site allows for the increase in the activity of SAT in response to increased demand (15).…”

Section: K Dsupporting

confidence: 84%

“…OAS, efficiently dissociates the CS complex, whereas bisulfide stabilizes it (20,21). Furthermore, OASS activity is decreased in CS (34) down to 5% of the value for the uncomplexed enzyme in E. coli and to about 50% in S. typhimurium (21). Opposed to the report for CS in E. coli (35), plant SAT is activated in CS, mainly as a result of an increase in k cat /K AcCoA (15).…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, OASS activity is decreased in CS (34) down to 5% of the value for the uncomplexed enzyme in E. coli and to about 50% in S. typhimurium (21). Opposed to the report for CS in E. coli (35), plant SAT is activated in CS, mainly as a result of an increase in k cat /K AcCoA (15). Studies in Arabidopsis have suggested a sulfur-sensing role for CS (20,47).…”

Section: Discussionmentioning

confidence: 99%

“…k 4 /k 3 . A value of 0.15 nM was measured for the K d overall of the complex in E. coli (35), whereas a value of Ͻ2 nM was estimated for CS from H. influenzae (8). Thus, for the value of 0.15 nM, Equations 6 and 7 are achieved,…”

Section: K Dmentioning

confidence: 99%

“…However, it is well known that the C terminus of SAT (Fig. 1C) plays a major role in complex formation (9,21,(33)(34)(35), penetrating inside the active site of OASS and binding at the ␣-carboxylate subsite of the substrate OAS. Simulations of complex formation suggested a role for electrostatic interactions and led to a proposed model for the structure of CS (36).…”

mentioning

confidence: 99%

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A Two-step Process Controls the Formation of the Bienzyme Cysteine Synthase Complex

Salsi

Campanini

Bettati

et al. 2010

Journal of Biological Chemistry

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The regulation of enzyme activity through the transient formation of multiprotein assemblies plays an important role in the control of biosynthetic pathways. One of the first regulatory complexes to be discovered was cysteine synthase (CS), formed by the pyridoxal 5-phosphate-dependent enzyme O-acetylserine sulfhydrylase (OASS) and serine acetyltransferase (SAT). These enzymes are at the branch point of the sulfur, carbon, and nitrogen assimilation pathways. Understanding the mechanism of complex formation helps to clarify the role played by CS in the regulation of sulfur assimilation in bacteria and plants. To this goal, stopped-flow fluorescence spectroscopy was used to characterize the interaction of SAT with OASS, at different temperatures and pH values, and in the presence of the physiological regulators cysteine and bisulfide. Results shed light on the mechanism of complex formation and regulation, so far poorly understood. Cysteine synthase assembly occurs via a two-step mechanism involving rapid formation of an encounter complex between the two enzymes, followed by a slow conformational change. The conformational change likely results from the closure of the active site of OASS upon binding of the SAT C-terminal peptide. Bisulfide, the second substrate and a feedback inhibitor of OASS, stabilizes the CS complex mainly by decreasing the back rate of the isomerization step. Cysteine, the product of the OASS reaction and a SAT inhibitor, slightly affects the kinetics of CS formation leading to destabilization of the complex.

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Section: K Dsupporting

confidence: 84%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: K Dmentioning

confidence: 99%

mentioning

confidence: 99%

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A Two-step Process Controls the Formation of the Bienzyme Cysteine Synthase Complex

Salsi

Campanini

Bettati

et al. 2010

Journal of Biological Chemistry

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Proteins Containing Nonnatural Amino Acids

Sisido

2002

Biopolymers Online

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Introduction Historical Outline Extension of Amino Acids Chemical Aminoacylation Extension of Codons (Four‐base Codons) Adaptability of Four‐base Codons in the Ribosome System and Extension to Five‐base Codons Nonnatural Base Pairs for Codon Extension In‐vitro Protein Synthesis in the Presence of tRNAs that are Amino‐acylated with Nonnatural Amino Acids Purification and Identification of Nonnatural Mutants Multiple Incorporation of Nonnatural amino acids by using Different Orthogonal Four‐base Codons Mutants that Contain a Single Nonnatural Amino Acid at Random Positions Combination of In‐vitro Synthesis and Chemical Synthesis for Screening Nonnatural Mutants and for Large‐scale Production In‐vivo Synthesis of Nonnatural Mutants Examples of Specialty Functions of Nonnatural Mutants Fluorescence Labeling Electron Transfers Inside Protein Frameworks Outlook and Perspectives Acknowledgments

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Cysteine biosynthesis contributes to β-methylamino-l-alanine tolerance in Escherichia coli

Italiano

Violi

et al. 2021

Research in Microbiology

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Untitled

Cited by 15 publications

References 8 publications

A Two-step Process Controls the Formation of the Bienzyme Cysteine Synthase Complex

A Two-step Process Controls the Formation of the Bienzyme Cysteine Synthase Complex

Proteins Containing Nonnatural Amino Acids

Cysteine biosynthesis contributes to β-methylamino-l-alanine tolerance in Escherichia coli

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