Evidence map›Paper›PMID 25156536›Full record

ArticleMolecular biology reports2014

Purification and biochemical characterization of DnaK and its transcriptional activator RpoH from Neisseria gonorrhoeae.

Shalini Narayanan, Simone A Beckham, John K Davies, Anna Roujeinikova

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Article in Molecular biology reports, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed, 4 citations in OpenAlex.

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4 · The record

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PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors at 2 institutions in 1 country.

Shalini NarayananDepartment of Microbiology, Monash University, Clayton, VIC, 3800, Australia.
Simone A Beckham
John K Davies
Anna Roujeinikova
Monash University · AUAustralian Regenerative Medicine Institute · AU

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

DnaK plays a central role in stress response in the important human pathogen Neisseria gonorrhoeae. The genes encoding the DnaK chaperone machine (DnaK/DnaJ/GrpE) in N. gonorrhoeae are transcribed from RpoH (σ(32))-dependent promoters. In this study, we cloned, purified and biochemically characterised N. gonorrhoeae DnaK (NgDnaK) and RpoH. The NgDnaK and RpoH sequences are 73 and 50 % identical to the sequences of their respective E. coli counterparts. Similar to EcDnaK, nucleotide-free NgDnaK exists as a mix of monomers, dimers and higher oligomeric species in solution, and dissociates into monomers on addition of ATP. Like E. coli σ(32), RpoH of N. gonorrhoeae is monomeric in solution. Kinetic analysis of the basal ATPase activity of purified NgDnaK revealed a V max of 193 pmol phosphate released per minute per microgram DnaK (which is significantly higher than reported basal ATPase activity of EcDnaK), and the turnover number against ATP was 0.4 min(-1) under our assay conditions. Nucleotide-free NgDnaK bound a short model substrate, NR-peptide, with micromolar affinity close to that reported for EcDnaK. Our analysis showed that interaction between N. gonorrhoeae RpoH and DnaK appears to be ATP-dependent and non-specific, in stark contrast to the E. coli DnaK system where σ(32) and DnaK interact as monomers even in the absence of ATP. Sequence comparison showed that the DnaK-binding site of σ(32) is not conserved in RpoH. Our findings suggest that the mechanism of DnaK/RpoH recognition in N. gonorrhoeae is different from that in E. coli.

Indexed as

Amino Acid SequenceBacterial ProteinsCloning, MolecularHeat-Shock ProteinsHSP70 Heat-Shock ProteinsKineticsMolecular Sequence DataNeisseria gonorrhoeaePromoter Regions, GeneticSigma FactorBacterial ProteinsHeat-Shock Proteinsheat-shock sigma factor 32HSP70 Heat-Shock ProteinsSigma Factor

Identifiers

PMID25156536
OpenAlexW2010145503

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.