Characterization of devH, a gene encoding a putative DNA binding protein required for heterocyst function in Anabaena sp strain PCC 7120
Characterization of devH, a gene encoding a putative DNA binding protein required for heterocyst function in Anabaena sp strain PCC 7120
复制标题
DOI：
10.1128/jb.182.12.3572-3581.2000
复制
发表时间：
2000-06-01
影响因子：
3.2
通讯作者：
Curtis, SE
中科院分区：
文献类型：
--
作者：
Hebbar, PB;Curtis, SE
devH 基因是在鱼腥藻筛选中鉴定出来的。菌株 PCC 7120 序列，其转录本在异形细胞发育过程中丰度增加。 devH的产物含有与环AMP受体蛋白家族成员的DEM结合域相似的螺旋-转角-螺旋蛾，该蛋白与蓝藻转录激活因子NtcA关系最为密切。 devH 转录本在营养细胞中几乎检测不到，并且在氮饥饿后被诱导大约五倍。两种发育突变体 hetR 和 ntCA 中不存在这种诱导。该基因表达为具有多个 5' 末端的单顺反子转录物，并且与 devH 5' 端相似的 500 bp 区域显示出在体内具有启动子活性。 devH 基因 aas 通过在开放阅读框中整合质粒序列而插入失活。 devH突变体的氮饥饿诱导野生型形态的杂胞；但突变体在没有固定氮的情况下是不能生存的，并且不能有氧还原乙炔。
The devH gene was identified in a screen for Anabaena sp. strain PCC 7120 sequences whose transcripts increase in abundance during a heterocyst development time course. The product of devH contains a helix-turn-helix moth similar to the DEM binding domain of members of the cyclic AMP receptor protein family, and the protein is most closely related to the cyanobacterial transcriptional activator NtcA. devH transcripts are barely detectable in vegetative cells and are induced approximately fivefold after nitrogen starvation. This induction is absent in the two developmental mutants hetR and ntCA. The gene is expressed as monocistronic transcripts with multiple 5' termini, and the similar to 500-bp region 5' to devH was shown to have promoter activity in vivo. The devH gene aas insertionally inactivated by the integration of plasmid sequences within the open reading frame. Nitrogen starvation of the devH mutant induces heterocysts of wild-type morphology; but the mutant is inviable in the absence of fixed nitrogen and unable to reduce acetylene aerobically.