摘要
对嗜冷弧菌（Psychrophicvibrto）2693菌株编码天冬氨酸氨甲酸基转移酶（Aspartate－transcarbamoylas──ATCase）的基因进行了克隆，并对其核着酸序列进行了分析。菌株2693的ATCase由pyrBI操纵子组成，pyrB编码催化链，pyrI编码调节链。催化及调节多肽链由一条单一的双顺反操纵子编码，在同一启动基因控制之下进行转录。pyrB的3’—端紧临pyrI的5’-端，两个编码区之间只有4个碱基间隔。
The gene encoding for aspartate transcarbamoylase (ATCase) from Psychrophilicvibrio, strain 2693 was cloned and sequenced. The sequence revealed the existence oftwo gene encoding respectively for a catalytic chain (pyrB) and a regulatory chain(pyr I). The catalytic and regulatory polypeptide chains of Vibrio 2693 ATCase areencoded by a single pyrBI bicistronic operon, and appear to be transcribed under thecontrol of the same promoter. The 3' -terminus of the catalytic cistron (pyrB) isadjacent to the. 5'-terminus of the regulatory cistron, these is only a 4 bp spacebetween the two coding regions.
