[Cloning and sequence analysis of ATCase genes from Psychrophilic vibrio]

The gene encoding for aspartate transcarbamoylase (ATCase) from Psychrophilic vibrio, strain 2693 was cloned and sequenced. The sequence revealed the existence of two gene encoding respectively for a catalytic chain (pyrB) and a regulatory chain (pyr I). The catalytic and regulatory polypeptide chains of Vibrio 2693 ATCase are encoded by a single pyrBI bicistronic operon, and appear to be transcribed under the control of the same promoter. The 3'-terminus of the catalytic cistron (pyrB) is adjacent to the 5'-terminus of the regulatory cistron, these is only a 4 bp space between the two coding regions.