Bibikov S I, Biran R, Rudd K E, Parkinson J S
Biology Department, University of Utah, Salt Lake City 84112, USA.
J Bacteriol. 1997 Jun;179(12):4075-9. doi: 10.1128/jb.179.12.4075-4079.1997.
The newly discovered aer locus of Escherichia coli encodes a 506-residue protein with an N terminus that resembles the NifL aerosensor and a C terminus that resembles the flagellar signaling domain of methyl-accepting chemoreceptors. Deletion mutants lacking a functional Aer protein failed to congregate around air bubbles or follow oxygen gradients in soft agar plates. Membranes with overexpressed Aer protein also contained high levels of noncovalently associated flavin adenine dinucleotide (FAD). We propose that Aer is a flavoprotein that mediates positive aerotactic responses in E. coli. Aer may use its FAD prosthetic group as a cellular redox sensor to monitor environmental oxygen levels.
新发现的大肠杆菌aer基因座编码一种含有506个氨基酸残基的蛋白质，其N端类似于固氮调节蛋白NifL的氧传感器，C端类似于甲基接受型化学感受器的鞭毛信号结构域。缺乏功能性Aer蛋白的缺失突变体无法在气泡周围聚集，也无法在软琼脂平板中沿着氧梯度移动。过表达Aer蛋白的细胞膜还含有高水平的非共价结合的黄素腺嘌呤二核苷酸（FAD）。我们提出，Aer是一种黄素蛋白，介导大肠杆菌中的正向趋氧反应。Aer可能利用其FAD辅基作为细胞氧化还原传感器来监测环境中的氧水平。
