Evidence for a dynamic and transient pathway through the TAT protein transport machinery.

ABSTRACT: Tat systems transport completely folded proteins across ion-tight membranes. Three membrane proteins comprise the Tat machinery in most systems. In thylakoids, cpTatC and Hcf106 mediate precursor recognition, whereas Tha4 facilitates translocation. We used chimeric precursor proteins with unstructured peptides and folded domains to test predictions of competing translocation models. Two models invoke protein-conducting channels, whereas another model proposes that cpTatC pulls substrates through a patch of Tha4 on the lipid bilayer. The thylakoid system transported unstructured peptide substrates alone or when fused to folded domains. However, larger substrates stalled before completion, some with amino- and carboxyl-folded domains on opposite sides of the membrane. The length of the precu

SUBMITTER: Cline K 

PROVIDER: S-EPMC1914107 | biostudies-literature | 2007 Jul

REPOSITORIES: biostudies-literature