Kosono S, Morotomi S, Kitada M, Kudo T
Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Biochim Biophys Acta. 1999 Jan 5;1409(3):171-5. doi: 10.1016/s0005-2728(98)00157-1.
Bacillus subtilis was revealed to have a homologous region to the DNA fragment responsible for alkaliphily of alkaliphilic Bacillus sp. C-125 on the genome, as reported previously [1]. The yufT gene on the B. subtilis genome showed a significant similarity with ORF1 of Bacillus sp. C-125, which is related to membrane potential (DeltaPsi)-driven Na+/H+ antiport activity and is important for pH homeostasis in an alkaline condition. Disruption of the yufT gene resulted in the decrease of Na+/H+ antiport activity, and the growth of the yufT disrupted strain was impaired with an increase in the external Na+ concentration. We conclude that the yufT gene encodes a Na+/H+ antiporter, which has a dominant role in the extrusion of cytotoxic Na+.
如先前报道[1]，研究发现枯草芽孢杆菌基因组上存在一段与嗜碱芽孢杆菌C-125负责嗜碱性的DNA片段的同源区域。枯草芽孢杆菌基因组上的yufT基因与芽孢杆菌C-125的开放阅读框1（ORF1）具有显著相似性，ORF1与膜电位（ΔΨ）驱动的Na+/H+反向转运活性相关，对碱性条件下的pH稳态至关重要。yufT基因的破坏导致Na+/H+反向转运活性降低，且yufT基因破坏菌株的生长受到损害，同时外部Na+浓度增加。我们得出结论，yufT基因编码一种Na+/H+反向转运蛋白，其在细胞毒性Na+的外排中起主导作用。
