Sequence for human argininosuccinate synthetase cDNA.

The nucleotide sequence for human argininosuccinate synthetase cDNA was determined by analysis of six clones isolated from a single experiment. The sequence covered 1623 nucleotides including 76 bases of poly(A) and contained a 1236 nucleotide open reading frame encoding a protein of 46,434 daltons. In one cDNA isolate, a cloning artifact or perhaps RNA polymerase error involving addition of an A in a region of six A's within the coding sequence was documented. Single base variations in the 3' untranslated region were examined in detail since detection of DNA polymorphisms in the cDNAs could imply over-expression of both alleles at the active locus in canavanine-resistant cells, i.e. a trans-acting mechanism for enzyme overproduction. However, the sequence from five cDNAs suggested some single base artifacts, and DNA polymorphism remains uncertain. The occurrence of three tandem arginine codons in the 5' untranslated region of the cDNA suggested the possibility of an interaction of arginyl-tRNA with mRNA to regulate RNA processing or half-life as a mechanism for arginine-mediated repression.