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Updated: Jul 12, 2026

Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays
Published on: September 28, 2018
Protein transport in chloroplasts - targeting to the intermembrane space
Lea Vojta1, Jürgen Soll, Bettina Bölter
1University of Munich, Department of Botany, Munich, Germany.
Abstract:
The import of proteins destined for the intermembrane space of chloroplasts has not been investigated in detail up to now. By investigating energy requirements and time courses, as well as performing competition experiments, we show that the two intermembrane space components Tic22 and MGD1 (E.C. 2.4.1.46) both engage the Toc machinery for crossing the outer envelope, whereas their pathways diverge thereafter. Although MGD1 appears to at least partly cross the inner envelope, Tic22 very likely reaches its mature form in the intermembrane space without involving stromal components. Thus, different pathways for intermembrane space targeting probably exist in chloroplasts.
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