Condon C, Liveris D, Squires C, Schwartz I, Squires C L
Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
J Bacteriol. 1995 Jul;177(14):4152-6. doi: 10.1128/jb.177.14.4152-4156.1995.
Here we present evidence that only five of the seven rRNA operons present in Escherichia coli are necessary to support near-optimal growth on complex media. Seven rrn operons are necessary, however, for rapid adaptation to nutrient and temperature changes, suggesting it is the ability to adapt quickly to changing environmental conditions that has provided the selective pressure for the persistence of seven rrn operons in E. coli. We have also found that one consequence of rrn operon inactivation is a miscoordination of the concentrations of initiation factor IF3 and ribosomes.
在此我们提供证据表明,大肠杆菌中存在的七个rRNA操纵子中只有五个对于在复杂培养基上支持接近最佳生长是必要的。然而,七个rrn操纵子对于快速适应营养和温度变化是必需的,这表明正是快速适应不断变化的环境条件的能力为大肠杆菌中七个rrn操纵子的持续存在提供了选择压力。我们还发现rrn操纵子失活的一个后果是起始因子IF3和核糖体浓度的失调。