Lathigra R, O'Regan M, Kiely B, Boesten B, O'Gara F
Gene. 1986;44(1):89-96. doi: 10.1016/0378-1119(86)90046-6.
A cya-like gene encoding adenyl cyclase from Rhizobium meliloti was localized to a 0.8-kb PstI-EcoRI fragment by subcloning experiments. Experiments in Escherichia coli 'maxicells' identified a R. meliloti cya gene product of 28 kDa, which is significantly smaller than the corresponding protein from enteric bacteria. A control region for the expression of the cya gene in E. coli was found on an adjacent 2.6-kb BglII-BamHI sequence by insertional mutagenesis with Tn5 and phage MudI (ApR lac). The direction of transcription of the cya gene was also determined using a cya::MudIlac fusion. Promoter activity of this cya::lac fusion was not decreased when glucose was added to the culture. The R. meliloti cya gene is conserved among R. meliloti strains but no homology could be detected to other Rhizobium species or to E. coli in DNA hybridization experiments.
通过亚克隆实验，将来自苜蓿根瘤菌的编码腺苷酸环化酶的类cya基因定位到一个0.8kb的PstI - EcoRI片段上。在大肠杆菌“大细胞”中的实验鉴定出苜蓿根瘤菌cya基因产物为28kDa，这明显小于来自肠道细菌的相应蛋白质。通过用Tn5和噬菌体MudI（ApR lac）进行插入诱变，在相邻的2.6kb BglII - BamHI序列上发现了大肠杆菌中cya基因表达的一个控制区域。还使用cya::MudIlac融合确定了cya基因的转录方向。当向培养物中添加葡萄糖时，这种cya::lac融合的启动子活性并未降低。苜蓿根瘤菌cya基因在苜蓿根瘤菌菌株中是保守的，但在DNA杂交实验中未检测到与其他根瘤菌物种或大肠杆菌的同源性。
