Conservation and variation between Rhodobacter capsulatus and Escherichia coli Tat systems
- authored by
- Ute Lindenstrauß, Thomas Brüser
- Abstract
The Tat system allows the translocation of folded and often cofactor-containing proteins across biological membranes. Here, we show by an interspecies transfer of a complete Tat translocon that Tat systems are largely, but not fully, interchangeable even between different classes of proteobacteria. The Tat apparatus from the α-proteobacterium Rhodobacter capsulatus was transferred to a Tat-deficient Escherichia coli strain, which is a γ-proteobacterium. Similar to that of E. coli, the R. capsulatus Tat system consists of three components, rc-TatA, rc-TatB, and rc-TatC. A fourth gene (rc-tatF) is present in the rc-tatABCF operon which has no apparent relevance for translocation. The translational starts of rc-tatC and rc-tatF overlap in four nucleotides (ATGA) with the preceding tat genes, pointing to efficient translational coupling of rc-tatB, rc-tatC, and rc-tatF. We show by a variety of physiological and biochemical assays that the R. capsulatus Tat system functionally targets the E. coli Tat substrates TorA, AmiA, AmiC, and formate dehydrogenase. Even a Tat substrate from a third organism is accepted, demonstrating that usually Tat systems and Tat substrates from different proteobacteria are compatible with each other. Only one exceptional Tat substrate of E. coli, a membrane-anchored dimethyl sulfoxide (DMSO) reductase, was not targeted by the R. capsulatus Tat system, resulting in a DMSO respiration deficiency. Although the general features of Tat substrates and translocons are similar between species, the data indicate that details in the targeting pathways can vary considerably.
- Organisation(s)
-
Institute of Microbiology
- External Organisation(s)
-
Martin Luther University Halle-Wittenberg
- Type
- Article
- Journal
- Journal of Bacteriology
- Volume
- 188
- Pages
- 7807-7814
- No. of pages
- 8
- ISSN
- 0021-9193
- Publication date
- 11.2006
- Publication status
- Published
- Peer reviewed
- Yes
- ASJC Scopus subject areas
- Microbiology, Molecular Biology
- Electronic version(s)
-
https://doi.org/10.1128/JB.01139-06 (Access:
Open)