Chang F N, Chang C N, Paik W K
J Bacteriol. 1974 Nov;120(2):651-6. doi: 10.1128/jb.120.2.651-656.1974.
Escherichia coli was grown in a medium containing [1-(14)C]methionine and [methyl-(3)H]methionine, and the (3)H/(14)C ratio was determined for each of the ribosomal proteins derived from the 70S ribosome. Evidence indicates that six proteins from the 50S subunit were methylated: L7, L9, L11, L12, L18, and L33. Methylation of several other 50S proteins (such as L1, L3, L5, etc.) may also occur. The methylated amino acids in protein L11 have been characterized further and found to be predominately epsilon-trimethyllysine. A small amount of a compound tentatively identified as N(G), N'(G)-dimethylarginine was also detected.
将大肠杆菌培养在含有[1-(14)C]甲硫氨酸和[甲基-(3)H]甲硫氨酸的培养基中，并测定了源自70S核糖体的每种核糖体蛋白的(3)H/(14)C比值。有证据表明，50S亚基的六种蛋白质发生了甲基化：L7、L9、L11、L12、L18和L33。其他几种50S蛋白质（如L1、L3、L5等）也可能发生甲基化。蛋白质L11中的甲基化氨基酸已得到进一步鉴定，发现主要是ε-三甲基赖氨酸。还检测到少量初步鉴定为N(G)，N'(G)-二甲基精氨酸的化合物。
