The α-helix of the second chromodomain of the 43 kDa subunit of the chloroplast signal recognition particle facilitates binding to the 54 kDa subunit

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• 作者：Rebecca Hermkes ; Silke Funke ; Christine Richter ; Jü ; rgen Kuhlmann and Danja Schü ; nemann
• 关键词：Signal recognition particle ; Chloroplast ; cpSRP43 ; Chromodomain ; Protein transport
• 刊名：FEBS Letters
• 出版年：2006
• 出版时间：29 May 2006
• 年：2006
• 卷：580
• 期：13
• 页码：3107-3111
• 全文大小：236 K

文摘

Chloroplasts of higher plants contain a unique signal recognition particle (cpSRP) that consists of two proteins, cpSRP54 and cpSRP43. CpSRP43 is composed of a four ankyrin repeat domain and three functionally distinct chromodomains (CDs). In this report we confirm previously published data that the second chromodomain (CD2) provides the primary binding site for cpSRP54. However, quantitative binding analysis demonstrates that cpSRP54 binds to CD2 significantly less efficiently than it binds to full-length cpSRP43. Further analysis of the binding interface of cpSRP by mutagenesis studies and a pepscan approach demonstrates that the C-terminal α-helix of CD2 facilitates binding to cpSRP54.