Randall L L, Hardy S J, Josefsson L G
Proc Natl Acad Sci U S A. 1978 Mar;75(3):1209-12. doi: 10.1073/pnas.75.3.1209.
Arabinose-binding protein, maltose-binding protein, and lambda receptor are synthesized in vitro on membrane-bound polysomes from Escherichia coli. All three proteins are exported from the cytoplasm of E. coli and all three are made in vitro in a form a few thousand daltons larger than the authentic protein. The larger form of arabinose-binding protein is also detected in vivo by pulse labeling. It is concluded that the larger forms of the exported proteins are precursors containing an extra sequence. In contrast to the above, when the intracellular protein elongation factor Tu is synthesized in vitro on free polysomes, it is not detectably larger than the authentic form.
阿拉伯糖结合蛋白、麦芽糖结合蛋白和λ受体在体外由大肠杆菌的膜结合多核糖体合成。这三种蛋白质都从大肠杆菌细胞质中输出，并且这三种蛋白质在体外合成时的形式比真实蛋白质大几千道尔顿。通过脉冲标记在体内也检测到了较大形式的阿拉伯糖结合蛋白。得出的结论是，输出蛋白的较大形式是含有额外序列的前体。与上述情况相反，当细胞内蛋白质延伸因子Tu在游离多核糖体上体外合成时，它与真实形式相比没有明显更大。
