Transport and proofreading of proteins by the twin-arginine translocation (Tat) system in bacteria
Robinson, Colin, Matos, Cristina F. R. O., Beck, Daniel, Ren, Chao, Ph.D., Lawrence, Janna, Vasisht, Nishi and Mendel, Sharon. (2011) Transport and proofreading of proteins by the twin-arginine translocation (Tat) system in bacteria. Biochimica et Biophysica Acta (BBA) - Biomembranes, Vol.1808 (No.3). pp. 876-884. ISSN 0005-2736Full text not available from this repository.
Official URL: http://dx.doi.org/10.1016/j.bbamem.2010.11.023
The twin-arginine translocation (Tat) system operates in plant thylakoid membranes and the plasma membranes of most free-living bacteria. In bacteria, it is responsible for the export of a number of proteins to the periplasm, outer membrane or growth medium, selecting substrates by virtue of cleavable N-terminal signal peptides that contain a key twin-arginine motif together with other determinants. Its most notable attribute is its ability to transport large folded proteins (even oligomeric proteins) across the tightly sealed plasma membrane. In Gram-negative bacteria, TatABC subunits appear to carry out all of the essential translocation functions in the form of two distinct complexes at steady state: a TatABC substrate-binding complex and separate TatA complex. Several studies favour a model in which these complexes transiently coalesce to generate the full translocase. Most Gram-positive organisms possess an even simpler "minimalist" Tat system which lacks a TatB component and contains, instead, a bifunctional TatA component. These Tat systems may involve the operation of a TatAC complex together with a separate TatA complex, although a radically different model for TatAC-type systems has also been proposed. While bacterial Tat systems appear to require the presence of only a few proteins for the actual translocation event, there is increasing evidence for the operation of ancillary components that carry out sophisticated "proofreading" activities. These activities ensure that redox proteins are only exported after full assembly of the cofactor, thereby avoiding the futile export of apo-forms. This article is part of a Special Issue entitled Protein translocation across or insertion into membranes. (C) 2011 Elsevier B.V. All rights reserved.
|Item Type:||Journal Article|
|Subjects:||Q Science > Q Science (General)|
|Divisions:||Faculty of Science > Life Sciences (2010- )|
|Journal or Publication Title:||Biochimica et Biophysica Acta (BBA) - Biomembranes|
|Number of Pages:||9|
|Page Range:||pp. 876-884|
|Access rights to Published version:||Restricted or Subscription Access|
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