Interaction of tetraiodofluorescein with a modified form of aspartate transcarbamylase.

Aspartate transcarbamylase from the hyperthermophilic eubacterium Thermotoga maritima: fused catalytic and regulatory polypeptides form an allosteric enzyme.

In the allosteric aspartate transcarbamylase (ATCase) from the hyperthermophilic eubacterium Thermotoga maritima, the catalytic and regulatory functions, which in class B ATCases are carried out by specialized polypeptides, are combined on a single type of polypeptide assembled in trimers. The ATCases from T. maritima and Treponema denticola present intriguing similarities, suggesting horizonta...

Interaction of aspartate transcarbamylase with regulatory nucleotides.

The molecular basis of ornithine transcarbamylase deficiency: modelling the human enzyme and the effects of mutations.

Human ornithine transcarbamylase is a trimer with 46% amino acid sequence homology to the catalytic subunit of E coli aspartate transcarbamylase. Secondary structure predictions, distributions of hydrophilic and hydrophobic regions, and the pattern of conserved residues suggest that the three dimensional structures of the two proteins are likely to be similar. A three dimensional model of ornit...

Control of Uracil Synthesis by Arginine in Escherichia Coli.

Ben-Ishai, Ruth (Israel Institute of Technology, Haifa), Michal Lahav, and Ada Zamir. Control of uracil synthesis by arginine in Escherichia coli. J. Bacteriol. 87:1436-1442. 1964.-It is shown that arginine affects uracil biosynthesis in Escherichia coli. The effect of arginine on uracil synthesis was analyzed by following the changes in the level of aspartate transcarbamylase, the first specif...

Functionally important arginine residues of aspartate transcarbamylase.

The reaction of phenylglyoxal with aspartate transcarbamylase and its isolated catalytic subunit results in complete loss of enzymatic activity (Kantrowitz, E. R., and Lipscomb, W. N. (1976) J. Biol. Chem. 251, 2688-2695). If N-(phosphonacetyl)-L-aspartate is used to protect the active site, we find that phenylglyoxal causes destruction of the enzyme's susceptibility to activation by ATP and in...