Purification and properties of Bacillus subtilis aspartate transcarbamylase.

Interactions of Cibacron Blue F3GA and nucleotides with Escherichia coli aspartate carbamoyltransferase and its subunits

“…The existence of this secondary nucleotide binding site might be of significance concerning the evolution of ATCases. It is well established that some bacteria like Bacillus subtilis (Bethell & Jones, 1964;Brabson & Switzer, 1975) possess an ATCase which is only the equivalent of the trimeric catalytic subunits and is not regulated by the nucleotide effectors. Furthermore, it has been shown that wheat germ ATCase is also a trimer of similar molecular weight (R. Yon, personal communication) which is sensitive to feedback inhibition by UMP (Yon, 1972).…”

Conversion of the noncooperative Bacillus subtilis aspartate transcarbamoylase into a cooperative enzyme by a single amino acid substitution

“…The trimeric aspartate transcarbamoylase from Bacillus subtilis, unlike the £. coli enzyme, does not show cooperativity for either substrate, and the activity of the enzyme is insensitive to both pyrimidine and purine nucleotides (Brabson & Switzer, 1975). Although the B. subtilis aspartate transcarbamoylase is not an allosteric enzyme, it is developmentally regulated.…”

“…coli enzyme (Lerner & Switzer, 1986). Furthermore, the native B. subtilis enzyme, like the E. coli catalytic subunit, is a trimer consisting of three identical polypeptide chains (Brabson & Switzer, 1975). Recently, the X-ray structure of the B. subtilis enzyme was determined at 3-Á resolution (Stevens et al, 1991).…”