Details
| Original language | English |
|---|---|
| Pages (from-to) | 42723-42730 |
| Number of pages | 8 |
| Journal | Journal of Biological Chemistry |
| Volume | 280 |
| Issue number | 52 |
| Publication status | Published - 30 Dec 2005 |
Abstract
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 substrate-bound TatBC complex detected in a bacterial system so far. A second TatBC complex near 440 kDa comprises most of the TatB and TatC but is devoid of RR-PhoA. The targeting of PhoA to the Tat translocon depends on the twin-arginine motif and results in severe growth defects. This physiological effect is likely to be due to proton leakage at the cytoplasmic membrane. The results point to mechanistic incompatibilities of the Tat system with unfolded proteins such as RR-PhoA. There does not exist an intrinsic quality control at the TatBC complex itself, although correct folding is inevitable for Tat-dependent translocation.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Biochemistry, Genetics and Molecular Biology(all)
- Molecular Biology
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology
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In: Journal of Biological Chemistry, Vol. 280, No. 52, 30.12.2005, p. 42723-42730.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Targeting of unfolded PhoA to the TAT translocon of Escherichia coli
AU - Richter, Silke
AU - Brüser, Thomas
N1 - Copyright: Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2005/12/30
Y1 - 2005/12/30
N2 - 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 substrate-bound TatBC complex detected in a bacterial system so far. A second TatBC complex near 440 kDa comprises most of the TatB and TatC but is devoid of RR-PhoA. The targeting of PhoA to the Tat translocon depends on the twin-arginine motif and results in severe growth defects. This physiological effect is likely to be due to proton leakage at the cytoplasmic membrane. The results point to mechanistic incompatibilities of the Tat system with unfolded proteins such as RR-PhoA. There does not exist an intrinsic quality control at the TatBC complex itself, although correct folding is inevitable for Tat-dependent translocation.
AB - 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 substrate-bound TatBC complex detected in a bacterial system so far. A second TatBC complex near 440 kDa comprises most of the TatB and TatC but is devoid of RR-PhoA. The targeting of PhoA to the Tat translocon depends on the twin-arginine motif and results in severe growth defects. This physiological effect is likely to be due to proton leakage at the cytoplasmic membrane. The results point to mechanistic incompatibilities of the Tat system with unfolded proteins such as RR-PhoA. There does not exist an intrinsic quality control at the TatBC complex itself, although correct folding is inevitable for Tat-dependent translocation.
UR - http://www.scopus.com/inward/record.url?scp=30044442673&partnerID=8YFLogxK
U2 - 10.1074/jbc.M509570200
DO - 10.1074/jbc.M509570200
M3 - Article
C2 - 16263723
AN - SCOPUS:30044442673
VL - 280
SP - 42723
EP - 42730
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 52
ER -