Tu G F, Reid G E, Zhang J G, Moritz R L, Simpson R J
Joint Protein Structure Laboratory, Ludwig Institute for Cancer Research (Melbourne Branch), Parkville, Victoria, Australia.
J Biol Chem. 1995 Apr 21;270(16):9322-6. doi: 10.1074/jbc.270.16.9322.
When murine interleukin-6 is overexpressed in Escherichia coli, a small population of molecules exhibits a novel C-terminal modification. Peptide mapping, electrospray ionization-mass spectrometry, and automated N- and C-terminal sequencing identified a peptide ("tag" peptide), -Ala-Ala-Asn-Asp-Glu-Asn-Tyr-Ala-Leu-Ala-Ala-COOH, encoded by a small metabolically stable RNA of E. coli (10Sa RNA) attached to truncated C termini of the recombinant protein. A mutant strain of E. coli in which the chromosomal 10Sa RNA gene (ssrA) is disrupted does not produce this C-terminal modification, confirming that the tag peptide originates from the ssrA gene.
当小鼠白细胞介素-6在大肠杆菌中过表达时，一小部分分子会呈现出一种新的C末端修饰。肽图谱分析、电喷雾电离质谱分析以及自动N末端和C末端测序鉴定出一种肽（“标签”肽），-Ala-Ala-Asn-Asp-Glu-Asn-Tyr-Ala-Leu-Ala-Ala-COOH，它由大肠杆菌的一种小的代谢稳定RNA（10Sa RNA）编码，并附着于重组蛋白的截短C末端。一种染色体10Sa RNA基因（ssrA）被破坏的大肠杆菌突变株不会产生这种C末端修饰，这证实了标签肽源自ssrA基因。
