Amino acid sequence of the catalytic subunit of aspartate transcarbamoylase from Escherichia coli

Abstract

We propose a primary structure for the catalytic subunit of aspartate transcarbamoylase (aspartate carbamoyltransferase; carbamoylphosphate: L-aspartate carbamoyltransferase, EC 2.1.3.2) from Escherichia coli based on amino acid sequences of fragments obtained by cyanogen bromide cleavage, by tryptic digestion of the succinylated polypeptide, and by chymotryptic and proteinase C digestion of the intact catalytic chain. The protein contains 310 amino acids and has a calculated molecular weight of 33,944. The negatively and positively charged residues are distributed uniformly, and there is no indication of charge clustering in the linear sequence.