Jürgen B, Schweder T, Hecker M
Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität Greifswald, Germany.
Mol Gen Genet. 1998 Jun;258(5):538-45. doi: 10.1007/s004380050765.
In Bacillus subtilis IS58 starved of glucose or exposed to heat shock, ethanol or salt stress, the sigmaB-dependent general stress protein GsiB is accumulated to a higher level than other general stress proteins. This high-level accumulation of GsiB can at least partially be attributed to the remarkably long half-life (approximately 20 min) of the gsiB mRNA. Analysis of different gsiB-lacZ fusions revealed that this stability is not determined by sequences at the 3' end of the transcript but rather by sequences upstream of the translational start codon. Site-directed mutagenesis established that a strong ribosome binding site was crucial for the increased stability of the gsiB mRNA. A comparison of the sequences upstream of the translational start codons of three general stress genes, gsiB, gspA and ctc, revealed a direct correlation between mRNA stability and the strength of their translational signals.
在枯草芽孢杆菌IS58中，当缺乏葡萄糖或受到热休克、乙醇或盐胁迫时，σB依赖的一般应激蛋白GsiB的积累水平高于其他一般应激蛋白。GsiB的这种高水平积累至少部分归因于gsiB mRNA极长的半衰期（约20分钟）。对不同的gsiB-lacZ融合体进行分析表明，这种稳定性不是由转录本3'端的序列决定的，而是由翻译起始密码子上游的序列决定的。定点诱变表明，强核糖体结合位点对于gsiB mRNA稳定性的提高至关重要。对三个一般应激基因gsiB、gspA和ctc的翻译起始密码子上游序列进行比较，发现mRNA稳定性与其翻译信号强度之间存在直接相关性。
