Efficient Twin Arginine Translocation (Tat) Pathway Transport of a Precursor Protein Covalently Anchored to Its Initial cpTatC Binding Site
Year: 2005
Type: article
Abstract: The thylakoid twin arginine protein translocation (Tat) system operates by a cyclical mechanism in which precursors bind to a cpTatC-Hcf106 receptor complex, which then recruits Tha4 to form the translocase. After translocation, the translocase disassembles. Here, we fine-mapped initial interactions between precursors and the components of the receptor complex. Precursors with (Tmd)Phe substitutions in the signal peptide and early mature domain were bound to thylakoids and photo-cross-linked to components. cpTatC and Hcf106 were found to interact with different regions of the signal peptide. cpTatC cross-linked strongly to residues in the immediate vicinity of the twin arginine motif. Hcf106 cross-linked less strongly to residues in the hydrophobic core and the early mature domain. To determine whether precursors must leave their initial sites of interaction during translocation, cross-linked precursors were subjected to protein transport conditions. tOE17 cross-linked to cpTatC was efficiently translocated, indicating that the mature domain of the precursor can be translocated while the signal peptide remains anchored to the receptor complex.
Source: Journal of Biological Chemistry
Authors: Fabien Gérard, Kenneth Cline
Institution: University of Florida
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1975615339