METHYLATION OF RIBOSOMAL-PROTEINS IN BACTERIA - EVIDENCE OF CONSERVED MODIFICATION OF THE EUBACTERIAL 50S SUBUNIT
METHYLATION OF RIBOSOMAL-PROTEINS IN BACTERIA - EVIDENCE OF CONSERVED MODIFICATION OF THE EUBACTERIAL 50S SUBUNIT
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DOI：
10.1128/jb.158.1.84-93.1984
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发表时间：
1984-01-01
影响因子：
3.2
通讯作者：
JEREZ, CA
中科院分区：
文献类型：
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作者：
AMARO, AM;JEREZ, CA
在[1-14C]蛋氨酸和/或[甲基- 3h]蛋氨酸存在下培养细胞后，测定嗜热脂肪芽孢杆菌、枯草芽孢杆菌、褐变单胞菌和角质盐杆菌的50S核糖体蛋白的甲基化。二维聚丙烯酰胺凝胶电泳分析显示，所研究的每个真细菌的甲基化蛋白的相对电泳迁移率相似。在一些微生物中已知的结构和功能同源的蛋白质都被甲基化了。因此，在嗜脂嗜热杆菌中，以下一组似乎参与肽基转移酶或聚苯丙氨酸合成活性的蛋白质被甲基化（括号中表示可能的大肠杆菌甲基化同源物）：BTL5（EL5）、BTL6（EL3）、BTL8（EL10）、BTL11（EL11）、BTL13（EL7L12）和BTL20b（EL16）。五聚体核糖体复合体BTL13.cntdot.BTL8，类似于大肠杆菌的复合体EL7L12.cntdot.EL10，含有甲基化蛋白。对甲基化程度最高的蛋白BSL11（枯草芽孢杆菌BSL11）和BTL11（嗜脂嗜热芽孢杆菌BTL11）中的甲基化氨基酸进行分析，发现存在.epsilon。- n -三甲基赖氨酸是两种蛋白质中主要的甲基化氨基酸，与大肠杆菌的已知数据一致。BSL11似乎含有三甲基丙氨酸，这是一种特殊的修饰氨基酸，以前只在大肠杆菌的EL11中发现过。这些结果和先前从其他细菌中获得的结果表明，核糖体蛋白甲基化具有高度的保守性，并表明真细菌核糖体中这些成分的修饰具有重要的作用，尽管尚不清楚。
Methylation of the 50S ribosomal proteins from Bacillus stearothermophilus, B. subtilis, Alteromonas espejiana and Halobacterium cutirubrum was measured after the cells were grown in the presence of [1-14C]methionine and/or [methyl-3H]methionine. Two-dimensional polyacrylamide gel electrophoretic analysis revealed similar relative electrophoretic mobilities of the methylated proteins from each eubacterium studied. Proteins known to be structurally and functionally homologous in several microorganisms were all methylated. Thus, the following group of proteins, which appear to be involved in peptidyltransferase or in poly(Phe)-synthesizing activity in B. stearothermophilus were methylated (possible Escherichia coli methylated homologs are indicated in parentheses): BTL5(EL5), BTL6(EL3), BTL8(EL10), BTL11(EL11), BTL13(EL7L12) and BTL20b(EL16). The pentameric ribosomal complex BTL13.cntdot.BTL8, analogous to the complex EL7L12.cntdot.EL10 of E. coli, contained methylated proteins. Analysis of the methylated amino acids in the most heavily methylated proteins, BSL11 from B. subtilis and BTL11 from B. stearothermophilus, showed the presence of .epsilon.-N-trimethyllysine as the major methylated amino acid in both proteins, in agreement with known data for E. coli. BSL11 appeared to contain trimethylalanine, a characteristic, modified amino acid previously described only in EL11 from E. coli. These results and those previously obtained from other bacteria indicate a high degree of conservation for ribosomal protein methylation and suggest an important, albeit unknown, role for the modification of these components in eubacterial ribosomes.