Escherichia coli ribosome-associated protein SRA, whose copy number increases during stationary phase
Escherichia coli ribosome-associated protein SRA, whose copy number increases during stationary phase
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DOI：
10.1128/jb.183.9.2765-2773.2001
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发表时间：
2001-05-01
影响因子：
3.2
通讯作者：
Wada, A
中科院分区：
文献类型：
--
作者：
Izutsu, K;Wada, C;Wada, A
蛋白质D以前已被证明是与大肠杆菌核糖体的自由基和高度还原的方法，二维聚丙烯酰胺凝胶电泳。在这项研究中，我们发现，蛋白D是专门存在于30 S核糖体亚基，其基因位于33.6分钟的E。coli的基因图谱，位于ompC和sfcA之间。该基因由45个密码子组成，编码5,096 Da的蛋白质。在生长过程中，每个核糖体颗粒的蛋白质D拷贝数变化，从指数期的0.1增加到稳定期的0.4。因此，蛋白D被命名为SRA（stationary-phase-induced ribosome-associated）蛋白，其基因被命名为sra。发现细胞内SRA蛋白的量主要在转录水平上控制：其转录在进入稳定期后迅速增加，并且部分依赖于替代性σ因子（σ S）。此外，全球监管机构，如因子倒位刺激（FIS），整合宿主因子（IHF），环AMP和ppGpp，被发现发挥作用，直接或间接在转录的稳定期的sra。
Protein D has previously been demonstrated to be associated with Escherichia coli ribosomes by the radical-free and highly reducing method of two-dimensional polyacrylamide gel electrophoresis. In this study, we show that protein D is exclusively present in the 30S ribosomal subunit and that its gene is located at 33.6 min on the E. coli genetic map, between ompC and sfcA. The gene consists of 45 codons, coding for a protein of 5,096 Da. The copy number of protein D per ribosomal particle varied during growth and increased from 0.1 in the exponential phase to 0.4 in the stationary phase. For these reasons, protein D was named SRA (stationary-phase-induced ribosome-associated) protein and its gene was named sra. The amount of SRA protein within the cell was found to be controlled mainly at the transcriptional level: its transcription increased rapidly upon entry into the stationary phase and was partly dependent on an alternative sigma factor (sigma S). In addition, global regulators, such as factor inversion stimulation (FIS), integration host factor (IHF), cyclic AMP, and ppGpp, were found to play a role either directly or indirectly in the transcription of sra in the stationary phase.