Preprotein recognition by the Toc complex
Open Access
- 5 February 2004
- journal article
- research article
- Published by Springer Nature in The EMBO Journal
- Vol. 23 (3) , 520-530
- https://doi.org/10.1038/sj.emboj.7600089
Abstract
The Toc core complex consists of the pore‐forming Toc75 and the GTPases Toc159 and Toc34. We confirm that the receptor form of Toc159 is integrated into the membrane. The association of Toc34 to Toc75/Toc159 is GTP dependent and enhanced by preprotein interaction. The N‐terminal half of the pSSU transit peptide interacts with high affinity with Toc159, whereas the C‐terminal part stimulates its GTP hydrolysis. The phosphorylated C‐terminal peptide of pSSU interacts strongly with Toc34 and therefore inhibits binding and translocation of pSSU into Toc proteoliposomes. In contrast, Toc159 recognises only the dephosphorylated forms. The N‐terminal part of the pSSU presequence does not influence binding to the Toc complex, but is able to block import into proteoliposomes through its interaction with Toc159. We developed a model of differential presequence recognition by Toc34 and Toc159.Keywords
This publication has 26 references indexed in Scilit:
- The Chloroplast Protein Import Receptors Toc34 and Toc159 Are Phosphorylated by Distinct Protein KinasesPublished by Elsevier ,2002
- Structural and Guanosine Triphosphate/Diphosphate Requirements for Transit Peptide Recognition by the Cytosolic Domain of the Chloroplast Outer Envelope Receptor, Toc34Biochemistry, 2002
- Protein translocon at the Arabidopsis outer chloroplast membraneBiochemistry and Cell Biology, 2001
- Targeting of an abundant cytosolic form of the protein import receptor at Toc159 to the outer chloroplast membraneThe Journal of cell biology, 2001
- The Signal Recognition ParticleAnnual Review of Biochemistry, 2001
- Topology Studies of the Chloroplast Protein Import Channel Toc75Biological Chemistry, 2000
- Initial Binding of Preproteins Involving the Toc159 Receptor Can Be Bypassed during Protein Import into ChloroplastsPlant Physiology, 2000
- The major protein import receptor of plastids is essential for chloroplast biogenesisNature, 2000
- Tic40, a New “Old” Subunit of the Chloroplast Protein Import TransloconJournal of Biological Chemistry, 1999
- Analysis of the Interactions of Preproteins with the Import Machinery over the Course of Protein Import into ChloroplastsThe Journal of cell biology, 1997