Complementation of bacterial SecE by a chloroplastic homologue

FEBS Letters

de Gier, Jan-Willem L.¹  Fröderberg, Linda¹  Röhl, Thomas²  van Wijk, Klaas-Jan² 

[1] Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, S-106 91 Stockholm, Sweden;Department of Plant Biology, Cornell University, Tower Road, Ithaca, NY 14853-5908, USA

关键词: Chloroplast;    Protein translocation;    Sec-translocase;    Escherichia coli;    cp;    chloroplastic;    IPTG;    isopropyl-1-thio-β-D-galactopyranoside;    SDS–PAGE;    sodium dodecylsulfate–polyacrylamide gel electrophoresis;    OmpA;    outer membrane protein A;   

DOI  :  10.1016/S0014-5793(01)02494-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The SecE protein is an essential component of the SecAYE-translocase, which mediates protein translocation across the cytoplasmic membrane in bacteria. In the thylakoid membranes of chloroplasts, a protein homologous to SecE, chloroplastic (cp) SecE, has been identified. However, the functional role of cpSecE has not been established experimentally. In this report we show that cpSecE in cells depleted for bacterial SecE (i) supports growth, (ii) stabilizes, just like bacterial SecE, the Sec-translocase core component SecY, and (iii) supports Sec-dependent protein translocation. This indicates that cpSecE can functionally replace bacterial SecE in vivo, and strongly suggests that the thylakoid membrane contains a SecAYE-like translocase with functional and structural similarities to the bacterial complex. This study further underscores the evolutionary link between chloroplasts and bacteria.

【 授权许可】

Unknown