Azide-resistant mutants of Escherichia coli alter the SecA protein, an azide-sensitive component of the protein export machinery.

Oliver, Donald B.; Cabelli, Robert J.; Dolan, Katherine M.; Jarosik, Gregory P.

doi:10.1073/pnas.87.21.8227

Cited by 300 publications

(254 citation statements)

References 36 publications

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“…Precursors of polypeptides were enriched by adding 5 mM sodium azide before labeling. Sodium azide inhibits SecA-dependent protein export (12,23). For analysis of in vivo inhibition of protein processing by globomycin, a specific inhibitor of signal peptidase II (18), the antibiotic was added before labeling to a final concentration of 100 ,ug/ml.…”

Section: Methodsmentioning

confidence: 99%

A lipoprotein of Yersinia enterocolitica facilitates ferrioxamine uptake in Escherichia coli

Bäumler

Hantke

1992

J Bacteriol

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A cloned fragment of Yersinia enterocolitica DNA complemented the defect in ferrioxamine B uptake of an Escherichia coli fluE mutant lacking the outer membrane high-affinity transport protein FhuE. Subcloning revealed that a 13.7-kDa outer membrane protein was required for complementation. The amino acid sequence deduced from the nucleotide sequence showed extensive homology to PCPHI, an outer membrane lipoprotein of Haemophilus influenzae. We therefore termed this protein PCPye. Plasmid-encoded pcpY mediated a low-affinity uptake of ferrioxamine B which may be caused by changes in the permeability of the outer membrane due to an overexpression of this outer membrane protein. A transposon insertion mutant in the plasmid-encoded pcpY gene was transferred into the chromosome of Y. enterocolitica. The resulting mutation had no effect on the high-affinity uptake of ferrioxamine B in Yersinia cells. Using the antibiotic ferrimycin we were able to isolate a Y. enterocolitica mutant lacking the high-affinity outer membrane receptor for ferrioxamine uptake, termed FoxA.Yersinia pestis, Yersinia enterocolitica, and Yersinia pseudotuberculosis are pathogenic in humans, causing diseases ranging from enteritis to black death by invasion of host tissues. Of these species, Y. enterocolitica is now the one most frequently isolated from human and animal infections.Ferrioxamine B can promote growth of Y. enterocolitica in vitro (6, 24) and in vivo (26) by acting as a source of iron for the organism. In strains which do not produce a siderophore (15), virulence in mice can be enhanced by addition of either iron dextran or the iron chelator desferrioxamine B (26). Desferrioxamine B is sold under the name Desferal as a licensed therapeutic substance for use in patients suffering from iron overload. Hence, it seems that treatment with desferrioxamine B increases the susceptibility of patients to yersiniosis (21) by serving as a siderophore, which helps Y. enterocolitica to obtain iron under the conditions of iron starvation in the host (7). It should be noted, though, that this effect could also be a consequence of the immunosuppressive activity of ferrioxamine B (2, 8).Siderophore uptake has been studied in detail in Escherichia coli. Each siderophore is transported across the outer membrane via a specific receptor protein. This process has been shown to be energy dependent and requires the action of the TonB protein, which is thought to couple the membrane potential of the cytoplasmic membrane with the outer membrane proteins by direct contact. Transport through the cytoplasmic membrane is mediated by a periplasmic binding protein-dependent transport system. This type of transport seems to be realized in various gram-negative genera for the uptake of vitamin B12 and siderophores (for a recent review, see reference 5). The coprogen outer membrane receptor protein FhuE (30) of E. coli mediates uptake of ferrioxamine B to a small extent.In this study we describe an attempt to clone the ferrioxamine B uptake system of Y. enterocolitic...

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Section: Methodsmentioning

confidence: 99%

A lipoprotein of Yersinia enterocolitica facilitates ferrioxamine uptake in Escherichia coli

Bäumler

Hantke

1992

J Bacteriol

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“…In addition to the F-ATPases, a number of other ATPases are inhibited by azide. They include the ABC transporters (34,35), the preprotein translocase SecA (36,37), DNA topoisomerase II␣ (38), and ecto-ATPases (39,40). In each case, azide probably enhances the inhibitory effect of ADP by stabilizing the ADP-bound state, and this enhancement has been demonstrated for the SecA translocase (41).…”

Section: ͚H͚i͉i(h) ϫ I(h)i͉͚͞h͚ii(h)i Where I(h)mentioning

confidence: 99%

How azide inhibits ATP hydrolysis by the F-ATPases

Bowler

Montgomery

Leslie

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

229

180

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In the structure of bovine F1-ATPase determined at 1.95-Å resolution with crystals grown in the presence of ADP, 5 -adenylylimidodiphosphate, and azide, the azide anion interacts with the ␤-phosphate of ADP and with residues in the ADP-binding catalytic subunit, ␤DP. It occupies a position between the catalytically essential amino acids, ␤-Lys-162 in the P loop and the ''arginine finger'' residue, ␣-Arg-373, similar to the site occupied by the ␥-phosphate in the ATP-binding subunit, ␤TP. Its presence in the ␤DP-subunit tightens the binding of the side chains to the nucleotide, enhancing its affinity and thereby stabilizing the state with bound ADP. This mechanism of inhibition appears to be common to many other ATPases, including ABC transporters, SecA, and DNA topoisomerase II␣. It also explains the stimulatory effect of azide on ATP-sensitive potassium channels by enhancing the binding of ADP.mitochondria ͉ oxidative phosphorylation ͉ inhibition ͉ mechanism

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“…This observation suggested that tig inactivation either alleviates the export defect or exposes the presecretory protein to degradation. To distinguish between these two possibilities, we measured the relative half-life of pre-Bla in MC4100 and HDB56 that were treated with sodium azide, an inhibitor of protein export (36). Bla was immunoprecipitated from cells that were pulse-labeled and subjected to either a 0 or 5-min chase.…”

Section: Fig 1 Disruption Of Tig Suppresses the Targeting Factor Rementioning

confidence: 99%

Trigger Factor Retards Protein Export in Escherichia coli

Lee

Bernstein

2002

Journal of Biological Chemistry

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Trigger factor (TF) is a ribosome-associated protein that interacts with a wide variety of nascent polypeptides in Escherichia coli. Previous studies have indicated that TF cooperates with DnaK to facilitate protein folding, but the basis of this cooperation is unclear. In this study we monitored protein export in E. coli that lack or overproduce TF to obtain further insights into its function. Whereas inactivation of genes encoding most molecular chaperones (including dnaK) impairs protein export, inactivation of the TF gene accelerated protein export and suppressed the need for targeting factors to maintain the translocation competence of presecretory proteins. Furthermore, overproduction of TF (but not DnaK) markedly retarded protein export. Manipulation of TF levels produced similar effects on the export of a cytosolic enzyme fused to a signal peptide. The data strongly suggest that TF has a unique ability to sequester nascent polypeptides for a relatively prolonged period. Based on our results, we propose that TF and DnaK promote protein folding by distinct (but complementary) mechanisms.Protein biogenesis in Escherichia coli is aided by a diverse set of specialized factors that interact with nascent polypeptides chains. Several of these factors ("molecular chaperones") promote the folding of cytoplasmic proteins by binding promiscuously to exposed hydrophobic surfaces and preventing aggregation (reviewed in Ref.

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Azide-resistant mutants of Escherichia coli alter the SecA protein, an azide-sensitive component of the protein export machinery.

Cited by 300 publications

References 36 publications

A lipoprotein of Yersinia enterocolitica facilitates ferrioxamine uptake in Escherichia coli

A lipoprotein of Yersinia enterocolitica facilitates ferrioxamine uptake in Escherichia coli

How azide inhibits ATP hydrolysis by the F-ATPases

Trigger Factor Retards Protein Export in Escherichia coli

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