• Corpus ID: 13509225

Location of three active site residues in the NH2-terminal sequence of the beta 2 subunit tryptophan synthase from Escherichia coli.

  title={Location of three active site residues in the NH2-terminal sequence of the beta 2 subunit tryptophan synthase from Escherichia coli.},
  author={William J. Higgins and Edith Wilson Miles and Thomas Fairwell},
  journal={The Journal of biological chemistry},
  volume={255 2},
The three known active site residues of the tryptophan synthase beta 2 subunit from Escherichia coli are shown to fall within 25 residues of each other in the primary sequence of the NH2-terminal region of the beta 2 subunit. These residues are: lysine-86, which forms a Schiff's base with pyridoxal phosphate; histidine-81 or histidine-85, which removes the alpha proton of L-serine; and cysteine-61, which reacts with bromoacetylpyridoxamine phosphate, an affinity label for the beta 2 subunit… 
19 Citations

Identification of three sites of proteolytic cleavage in the hinge region between the two domains of the beta 2 subunit of tryptophan synthase of Escherichia coli or Salmonella typhimurium.

Comparison studies of limited proteolysis by three proteinases show that Edman degradation can be effectively used with a protein of known sequence to analyze proteolytic digests that have at least four different amino-terminal sequences.

L-serine binds to arginine-148 of the beta 2 subunit of Escherichia coli tryptophan synthase.

It is concluded that the alpha-carboxyl group of L-serine and not the phosphate of pyridoxal phosphate binds to the essential arginyl residue in the beta 2 subunit.

The Quarternary Structure of Tryptophan Synthase from Escherichia coli

The radii of gyration, maximum dimensions and hydrated volumes calculated for the best models of the α and β2 subunits and the α2β2 complex agree reasonably well with the results of independent small-angle X-ray scattering studies.

The mechanism of tryptophan binding to tryptophan synthase from Escherichia coli.

It is suggested that at least two alterative modes of binding of L-tryptophan exist on the enzyme, and the effects of protons, indole and indolepropanol phosphate on the three rate processes explain the dependence of kcat on theThree non-competitive ligands.

Linkage of subunit interactions, structural changes, and energetics of coenzyme binding in tryptophan synthase.

Calorimetric titrations of the apo beta 2 subunit with PLP at 35 degrees C have shown that also at this temperature positive cooperativity between the two binding sites occurs and a complete set of site-specific thermodynamic parameters has been established.

Kinetic characterization of early intermediates in the folding of E. coli tryptophan‐synthase β2 subunit

The use of fluorescence energy transfer between an intrinsic energy donor and two chemically added acceptors to study intermediates in the folding of the β2 subunit of E. coli tryptophan‐synthase brings to five the number of intermediates which have been identified and ordered on the folding pathway of the dimeric β2subunit.