Mouz S, Merlin C, Springael D, Toussaint A
Laboratoire de Microbiologie, Université J. Fourier, Grenoble, France.
Mol Gen Genet. 1999 Dec;262(4-5):790-9. doi: 10.1007/s004380051142.
Tn4371, a 55-kb catabolic transposon originally isolated from Ralstonia eutropha A5, carries genes for the degradation of biphenyl/4-chlorobiphenyl, which are clustered on a 13-kb DNA segment located in the middle of the element. DNA sequencing revealed that two potential regulatory genes, bphR and bphS, border this region. Transcriptional fusion experiments using bphC as a reporter gene, Northern hybridization and primer extension analysis led to the conclusion that the transposon-encoded genes bphEFGA1A2A3BCD form an operon transcribed from a sigma70 promoter, pE. Transcription from pE was not influenced by deletion of the bphR gene of Tn4371, which should encode a LysR-like regulator. The bphS gene product negatively regulated pE, and displayed significant similarity to GntR-like regulators. This is the first reported example of a GntR-like regulator involved in the control of an aromatic degradation pathway.
Tn4371是一种最初从真养产碱菌A5中分离出的55kb分解代谢转座子，携带联苯/4-氯联苯降解基因，这些基因聚集在位于该元件中间的一个13kb DNA片段上。DNA测序显示，两个潜在的调控基因bphR和bphS位于该区域的边界。使用bphC作为报告基因的转录融合实验、Northern杂交和引物延伸分析得出结论，转座子编码的基因bphEFGA1A2A3BCD形成一个从σ70启动子pE转录的操纵子。来自pE的转录不受Tn4371的bphR基因缺失的影响，bphR基因应该编码一种类似LysR的调控因子。bphS基因产物对pE起负调控作用，并且与类似GntR的调控因子具有显著的相似性。这是首次报道的一个类似GntR的调控因子参与芳香族降解途径控制的例子。
