Thylakoid DeltapH-dependent precursor proteins bind to a cpTatC-Hcf106 complex before Tha4-dependent transport.

ABSTRACT: The thylakoid DeltapH-dependent pathway transports folded proteins with twin arginine-containing signal peptides. Identified components of the machinery include cpTatC, Hcf106, and Tha4. The reaction occurs in two steps: precursor binding to the machinery, and transport across the membrane. Here, we show that a cpTatC-Hcf106 complex serves as receptor for specific binding of twin arginine-containing precursors. Antibodies to either Hcf106 or cpTatC, but not Tha4, inhibited precursor binding. Blue native gel electrophoresis and coimmunoprecipitation of digitonin-solubilized thylakoids showed that Hcf106 and cpTatC are members of an approximately 700-kD complex that lacks Tha4. Thylakoid-bound precursor proteins were also associated with an approximately 700-kD complex and were coimmunopreci

SUBMITTER: Cline K 

PROVIDER: S-EPMC2196467 | biostudies-literature | 2001 Aug

REPOSITORIES: biostudies-literature