Halpin C, Elderfield P D, James H E, Zimmermann R, Dunbar B, Robinson C
Department of Biological Sciences, University of Warwick, Coventry, UK.
EMBO J. 1989 Dec 1;8(12):3917-21. doi: 10.1002/j.1460-2075.1989.tb08572.x.
Proteins which are transported across the bacterial plasma membrane, endoplasmic reticulum and thylakoid membrane are usually synthesized as larger precursors containing amino-terminal targeting signals. Removal of the signals is carried out by specific, membrane-bound processing peptidases. In this report we show that the reaction specificities of these three peptidases are essentially identical. Precursors of two higher plant thylakoid lumen proteins are efficiently processed by purified Escherichia coli leader peptidase. Processing of one precursor, that of the 23 kd photosystem II protein, by both the thylakoidal and E. coli enzymes generates the correct mature amino terminus. Similarly, leader (signal) peptides of both eukaryotic and prokaryotic origin are cleaved by partially purified thylakoidal processing peptidase. No evidence of incorrect processing was obtained. Both leader peptidase and thylakoidal peptidase are inhibited by a synthetic leader peptide.
穿过细菌质膜、内质网和类囊体膜运输的蛋白质通常作为含有氨基末端靶向信号的较大前体进行合成。信号的去除由特定的膜结合加工肽酶进行。在本报告中，我们表明这三种肽酶的反应特异性基本相同。两种高等植物类囊体腔蛋白的前体被纯化的大肠杆菌前导肽酶有效加工。类囊体酶和大肠杆菌酶对一种前体（23kd光系统II蛋白的前体）的加工产生了正确的成熟氨基末端。同样，真核和原核来源的前导（信号）肽都被部分纯化的类囊体加工肽酶切割。未获得错误加工的证据。前导肽酶和类囊体肽酶都被合成前导肽抑制。
