| Abstract Detail
Protein Targeting and Vesicular Trafficking Rounds, Caleb [1], Schnell, Danny [2]. The N-terminal acidic domain of atToc159 is responsible for forming distinct translocons in chloroplasts. Import of cytoplasmically translated preproteins into the chloroplast is essential for chloroplast biogenesis and the critical metabolic functions of the plastid. The formation of distinct protein import complexes play a role in regulating this process. These complexes, termed translocons, consist of two receptor GTPases and a pore protein. They include at least one member of the atToc159 family: atToc159, atToc132, atToc120, or atToc90. These receptors have been shown to bind specific subclasses of preproteins supporting the hypothesis that distinct translocons import subclasses of preproteins. In this report, we present evidence that the highly variable N-terminal portion of atToc159 family preprotein receptors determines the assembly of these specific complexes. Receptors lacking this N-terminal domain can fully complement the atToc159 T-DNA knockout mutant, though translocon assembly is altered. Receptors that include chimeric A domains form distinct translocons, and can complement some but not all of the functionality of the full-length atToc159. These findings support the hypothesis that the N-terminal domain serves to define structurally and functionally distinct import pathways into the chloroplast.
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1 - University of Massachusetts, Plant Biology, Lgrt1106, Amherst, MA, 01003
2 - University of Massachusetts, Department of Biochemistry and Molecular Biology
Keywords:
Chloroplast
protein import.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P22009
Abstract ID:264 |
