Studies of the function and location of two cysteines in the beta 2 subunit of tryptophan synthase.

@article{Higgins1978StudiesOT,
  title={Studies of the function and location of two cysteines in the beta 2 subunit of tryptophan synthase.},
  author={H. Higgins and E. W. Miles},
  journal={Biochemical and biophysical research communications},
  year={1978},
  volume={82 1},
  pages={
          265-72
        }
}
  • H. Higgins, E. W. Miles
  • Published 15 May 1978
  • Chemistry, Medicine
  • Biochemical and biophysical research communications
Abstract Our findings that the apo β2 subunit of tryptophan synthase of Escherichia coli is inactivated by the modification of one sulfhydryl residue per monomer by nitrothiocyanobenzoic acid and is reactivated by removal of the CN group indicate that the reactive sulfhydryl residue (SH-I) is essential for catalytic activity. SH-I is shown to be the same residue which was previously found to react with bromoacetylpyridoxamine phosphate and different from a sulfhydryl (SH-II) which reacts with N… 
8 Citations
Location of the reactive sulfhydryl residues in the primary sequence of the beta 2 subunit of tryptophan synthase of Escherichia coli.
TLDR
It is shown that the single sulfhydryl which reacts with N-ethylmaleimide in the presence of pyridoxal phosphate is cysteine-170.
Reaction of phenylglyoxal and (p-hydroxyphenyl) glyoxal with arginines and cysteines in the alpha subunit of tryptophan synthase.
TLDR
The finding that the substrate protects the single essential arginyl residue but not the two sulfhydryl groups is consistent with the observed kinetics of partial protection by substrate or by a substrate analogue, indole-3-propanol phosphate.
Neurospora tryptophan synthase. Characterization of the pyridoxal phosphate binding site.
TLDR
Tryptophan synthase from Neurospora crassa, a homodimer of two 75-kDa subunits, was shown to bind 1 mol of pyridoxal phosphate/mol of subunit with a calculated dissociation constant for pyridine, and the active site residue was determined to be lysine by high performance liquid chromatography analysis of the protein hydrolysate.
Kinetics of cooperative ligand binding to the apo beta 2 subunit of tryptophan synthase and its modulation by the alp ha subunit.
TLDR
The slow isonerization involved in the cooperative binding of the ligands to the intact apo beta 2 subunit is discussed in terms of local and concerted conformational changes involving the two autonomously folding domains of the beta protomer.
Tryptophan synthase: a multienzyme complex with an intramolecular tunnel.
TLDR
The combined results show that the switching of the enzyme between open and closed conformations couples the catalytic reactions at the alpha and beta active sites and prevents the escape of indole.
Molecular characterization of TRP1, a gene coding for tryptophan synthetase in the basidiomycete Coprinus cinereus.
TLDR
Comparison of exon boundaries in the C. cinereus sequence to the three-dimensional structure of Salmonella typhimurium TSase indicates that there is no simple correlation between exons and major functional domains in this protein.
Structural basis for catalysis by tryptophan synthase.
  • E. W. Miles
  • Chemistry, Medicine
    Advances in enzymology and related areas of molecular biology
  • 1991
Tryptophan synthase: structure, function, and subunit interaction.
  • E. W. Miles
  • Chemistry, Medicine
    Advances in enzymology and related areas of molecular biology
  • 1979

References

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Evidence that the essential, photosensitive histidyl residue in the beta2 subunit of tryptophan synthetase is in the pyridoxyl peptide.
  • E. W. Miles
  • Chemistry, Medicine
    Biochemical and biophysical research communications
  • 1974
TLDR
Pyridoxal 5′-phosphate sensitizes the photooxidation of a nearby, essential histidyl residue of Escherichia coli, resulting in photoinactivated tryptophan synthetase and two tryptic peptides are found in much lower amounts in the photoin activated enzyme.
The B protein of Escherichia coli tryptophan synthetase. I. Effects of sulfhydryl modification on enzymatic activities and subunit interaction.
  • E. W. Miles
  • Medicine, Chemistry
    The Journal of biological chemistry
  • 1970
Abstract Sulfhydryl modification of the B protein of Escherichia coli tryptophan synthetase has been carried out to investigate the role of sulfhydryl residues in the active center of this protein
Tryptophan synthetase 2 subunit. Primary structure of the pyridoxyl peptide from the Escherichia coli enzyme.
Abstract Radioactivity incorporated into an e-N-5'-phosphopyridoxyllysine residue of the β chain by reduction of the β2 holoenzyme with tritiated sodium borohydride appears in two tryptic peptides.
Isolation and characterization of independently folding regions of the beta chain of Escherichia coli tryptophan synthetase.
TLDR
It is shown that the beta2 subunit of Escherichia coli tryptophan synthetase can be separated after denaturation, and demonstrated that, upon mixing, these renatured fragments reassociate to form the ren atured nicked protein which, by all the physical and functional criteria used, is indistinguishable from the native nickedprotein.
Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4
Using an improved method of gel electrophoresis, many hitherto unknown proteins have been found in bacteriophage T4 and some of these have been identified with specific gene products. Four major
An improved method of counting radioactive acrylamide gels.
TLDR
A new method for counting sliced acrylamide gels by dissolving the sample at the relatively low temperature of 37° with a mixture of H 2 O 2 and NH 4 OH is described.
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