TY - JOUR

T1 - Conservation and variation between Rhodobacter capsulatus and Escherichia coli Tat systems

AU - Lindenstrauß, Ute

AU - Brüser, Thomas

N1 - Copyright: Copyright 2008 Elsevier B.V., All rights reserved.

PY - 2006/11

Y1 - 2006/11

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=33751087498&partnerID=8YFLogxK

U2 - 10.1128/JB.01139-06

DO - 10.1128/JB.01139-06

M3 - Article

C2 - 16980457

AN - SCOPUS:33751087498

VL - 188

SP - 7807

EP - 7814

JO - Journal of Bacteriology

JF - Journal of Bacteriology

SN - 0021-9193

IS - 22

ER -