Recombinant Expression of tatABC and tatAC Results in the Formation of Interacting Cytoplasmic TatA Tubes in Escherichia coli

The twin-arginine translocation (Tat) system of bacteria and plant plastids serves to translocate folded proteins across energized biological membranes. In Escherichia coli, the three components TatA, TatB, and TatC mediate this membrane passage. Here we demonstrate that TatA can assemble to form cl...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2008-09, Vol.283 (37), p.25281-25289
Main Authors: Berthelmann, Felix, Mehner, Denise, Richter, Silke, Lindenstrauss, Ute, Lünsdorf, Heinrich, Hause, Gerd, Brüser, Thomas
Format: Article
Language:English
Subjects:
Biochemistry - methods
Cytoplasm - metabolism
Escherichia coli - metabolism
Escherichia coli Proteins - biosynthesis
Gene Expression Regulation, Bacterial
Green Fluorescent Proteins - metabolism
Membrane Transport Proteins - biosynthesis
Microscopy, Confocal
Microscopy, Electron
Microscopy, Fluorescence
Models, Biological
Point Mutation
Recombinant Proteins - chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The twin-arginine translocation (Tat) system of bacteria and plant plastids serves to translocate folded proteins across energized biological membranes. In Escherichia coli, the three components TatA, TatB, and TatC mediate this membrane passage. Here we demonstrate that TatA can assemble to form clusters of tube-like structures in vivo. While the presence of TatC is essential for their formation, TatB is not required. The TatA tubes have uniform outer and inner diameters of about 11.5 nm and 6.7 nm, respectively. They align to form a crystalline-like structure in which each tube is surrounded by six TatA tubes. The tube structures become easily detectable even at only a 15-fold overexpression of the tatABC genes. The TatA tubes could also be visualized by fluorescence when untagged TatA was mixed with low amounts of TatA-GFP. The structures were often found in contact with the cell poles. Because TatC is most likely polar in E. coli, as demonstrated by a RR-dependent targeting of translocation-incompatible Tat substrates to the cell poles, and because TatC is required for the formation of aligned TatA tubes, it is proposed that the TatA tubes are initiated at polarly localized TatC.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M707757200