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Halophilic archaea thrive in environments with salt concentrations approaching saturation. However, little is known about the way in which these organisms stabilize their secreted proteins in such 'hostile' conditions. Here, we present data suggesting that the utilization of protein translocation pathways for protein secretion by the Halobacteriaceae(More)
The Tat (twin-arginine translocation) system of Escherichia coli serves to translocate folded proteins across the cytoplasmic membrane. The reasons established so far for the Tat dependence are cytoplasmic cofactor assembly and/or heterodimerization of the respective proteins. We were interested in the reasons for the Tat dependence of novel Tat substrates(More)
The twin-arginine translocation (Tat) system can translocate folded proteins across biological membranes. Among the known Tat-system components in Escherichia coli, TatC is the only protein with multiple trans-membrane domains. TatC is important for translocon interactions with Tat substrates. The knowledge of its membrane topology is therefore crucial for(More)
The Tat (twin-arginine translocation) system from Escherichia coli transports folded proteins with N-terminal twin-arginine signal peptides across the cytoplasmic membrane. The influence of general chaperones on Tat substrate targeting has not been clarified so far. Here we show that the chaperones SlyD and DnaK bind to a broad range of different Tat signal(More)
The phage shock protein A (PspA) of Escherichia coli stabilizes the cytoplasmic membrane under stress conditions. Here we demonstrate that PspA can form hollow spherical or prolate spheroidal particles of about 30-40nm diameter with a scaffold-like arrangement of protein subunits at the surface. The 'PspA-scaffold' is the basic structure that is common to(More)
In bacteria, two major pathways exist to secrete proteins across the cytoplasmic membrane. The general Secretion route, termed Sec-pathway, catalyzes the transmembrane translocation of proteins in their unfolded conformation, whereupon they fold into their native structure at the trans-side of the membrane. The Twin-arginine translocation pathway, termed(More)
The twin arginine translocation (Tat) system is a machinery which can translocate folded proteins across energy transducing membranes. Currently it is supposed that Tat substrates bind directly to Tat translocon components before a ApH-driven translocation occurs. In this review, an alternative model is presented which proposes that membrane integration(More)
In Escherichia coli, the Tat system does not translocate Tat signal sequence fused PhoA (RR-PhoA), as it requires disulfide formation for folding. Here we show that such a RR-PhoA construct can be efficiently targeted to the Tat translocon, but the transport is not completed. RR-PhoA is detectable in a 580-kDa TatBC-containing complex, which is the first(More)
Targeting of proteins to and translocation across the membranes is a fundamental biological process in all organisms. In bacteria, the twin arginine translocation (Tat) system can transport folded proteins. Here, we demonstrate in vivo that the high potential iron-sulfur protein (HiPIP) from Allochromatium vinosum is translocated into the periplasmic space(More)
Translocation of folded proteins across biological membranes can be mediated by the so-called 'twin-arginine translocation' (Tat) system. To be translocated, Tat substrates require N-terminal signal sequences which usually contain the eponymous twin-arginine motif. Here we report the first structural analysis of a twin-arginine signal sequence, the signal(More)