Lopes J M, Lawther R P
Biology Department, University of South Carolina, Columbia 29208.
Gene. 1989;76(2):255-69. doi: 10.1016/0378-1119(89)90166-2.
It has been previously demonstrated that the ilvGMEDA operon is expressed in vivo from the promoters ilvGp2 and ilvEp. An additional internal promoter is identified and designated ilvAp. This internal promoter, which allows independent expression of ilvA, has been analyzed both in vivo and in vitro. Our results indicate that: (1) ilvAp exists in both Escherichia coli K-12 and Salmonella typhimurium, as demonstrated by fusion to the galK reporter gene; (2) ilvAp is located in the distal coding sequence of ilvD; (3) the ilvAp sequences are not identical for these two bacterial species; (4) transcription from ilvAp of E. coli K-12 was demonstrated; (5) expression from ilvAp responds to the availability of oxygen; (6) potential 3' 5'-cyclic AMP receptor protein binding sites exist adjacent to ilvAp.
先前已经证明，ilvGMEDA操纵子在体内由启动子ilvGp2和ilvEp表达。另外一个内部启动子被鉴定并命名为ilvAp。这个允许ilvA独立表达的内部启动子已经在体内和体外进行了分析。我们的结果表明：（1）通过与galK报告基因融合证明，ilvAp存在于大肠杆菌K-12和鼠伤寒沙门氏菌中；（2）ilvAp位于ilvD的远端编码序列中；（3）这两种细菌的ilvAp序列不相同；（4）证明了大肠杆菌K-12的ilvAp进行转录；（5）ilvAp的表达对氧气的可利用性有反应；（6）在ilvAp附近存在潜在的3',5'-环腺苷酸受体蛋白结合位点。
