Biochemical characterization and redesign of the coenzyme specificity of a novel monofunctional NAD+-dependent homoserine dehydrogenase from the human pathogen Neisseria gonorrhoeae

The ability of Escherichia coli to use both nitrate and nitrite as terminal electron acceptors during anaerobic growth is mediated by the dual-acting two-component regulatory systems NarX-NarL and NarQ-NarP. In contrast, Neisseria gonorrhoeae responds only to nitrite: it expresses only NarQ-NarP. We have shown that although N. gonorrhoeae NarQ can phosphorylate E. coli NarL and NarP, the N. gonorrhoeae NarP is unable to regulate gene expression in E. coli. Mutagenesis experiments have revealed residues in E. coli NarQ that are essential for nitrate and nitrite sensing. Chimaeric proteins revealed domains of NarQ that are important for ligand sensing.

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A Periplasmic Thioredoxin-Like Protein Plays a Role in Defense against Oxidative Stress in Neisseria gonorrhoeae

Infection and Immunity ◽

10.1128/iai.00714-09 ◽

2009 ◽

Vol 77 (11) ◽

pp. 4934-4939 ◽

Cited By ~ 17

Author(s):

Maud E. S. Achard ◽

Amanda J. Hamilton ◽

Tarek Dankowski ◽

Begoña Heras ◽

Mark S. Schembri ◽

...

Keyword(s):

Neisseria Gonorrhoeae ◽

Bioinformatics Analysis ◽

Biochemical Characterization ◽

Gram Negative Bacteria ◽

Secondary Structure Analysis ◽

Disulfide Reduction ◽

Highly Sensitive ◽

Standard Redox Potential ◽

Disulfide Oxidoreductase

ABSTRACT Thioredoxin-like proteins of the TlpA/ResE/CcmG subfamily are known to face the periplasm in gram-negative bacteria. Using the tlpA gene of Bradyrhizobium japonicum as a query, we identified a locus (NGO1923) in Neisseria gonorrhoeae that encodes a thioredoxin-like protein (NG_TlpA). Bioinformatics analysis indicated that the predicted NG_TlpA protein contained a cleavable signal peptide at the N terminus, and secondary structure analysis identified a thioredoxin fold with a helical insertion (∼25 residues), similar to that found in B. japonicum TlpA but absent in cytoplasmic thioredoxins. Biochemical characterization of a recombinant form of NG_TlpA revealed a standard redox potential (E0′) of −206 mV. This property and the observation that the oxidized form of the protein exhibited greater thermal stability than the reduced species indicated that NG_TlpA is a reducing thioredoxin and not an oxidizing thiol-disulfide oxidoreductase like DsbA. The thioredoxin activity of NG_TlpA was confirmed in an insulin disulfide reduction assay. A tlpA mutant of N. gonorrhoeae strain 1291 was found to be highly sensitive to oxidative killing by paraquat and hydrogen peroxide, indicating an antioxidant role for the NG_TlpA in this bacterium. The tlpA mutant also exhibited reduced intracellular survival in human primary cervical epithelial cells.

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Complete Genome Sequence of Neisseria gonorrhoeae NCCP11945

Journal of Bacteriology ◽

10.1128/jb.00566-08 ◽

2008 ◽

Vol 190 (17) ◽

pp. 6035-6036 ◽

Cited By ~ 44

Author(s):

Gyung Tae Chung ◽

Jeong Sik Yoo ◽

Hee Bok Oh ◽

Yeong Seon Lee ◽

Sun Ho Cha ◽

...

Keyword(s):

Antibiotic Resistance ◽

Gene Transfer ◽

Horizontal Gene Transfer ◽

Neisseria Gonorrhoeae ◽

Genome Sequence ◽

Complete Genome Sequence ◽

Complete Genome ◽

Multidrug Resistant ◽

Human Pathogen ◽

Korean Patient

ABSTRACT Neisseria gonorrhoeae is an obligate human pathogen that is the etiological agent of gonorrhea. We explored variations in the genes of a multidrug-resistant N. gonorrhoeae isolate from a Korean patient in an effort to understand the prevalence, antibiotic resistance, and importance of horizontal gene transfer within this important, naturally competent organism. Here, we report the complete annotated genome sequence of N. gonorrhoeae strain NCCP11945.

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

Molecular Biology Reports ◽

10.1007/s11033-014-3689-1 ◽

2014 ◽

Vol 41 (12) ◽

pp. 7945-7953

Author(s):

Shalini Narayanan ◽

Simone A. Beckham ◽

John K. Davies ◽

Anna Roujeinikova

Keyword(s):

Neisseria Gonorrhoeae ◽

Biochemical Characterization ◽

Transcriptional Activator

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Identification of sRNAs expressed by the human pathogen Neisseria gonorrhoeae under disparate growth conditions

Frontiers in Microbiology ◽

10.3389/fmicb.2014.00456 ◽

2014 ◽

Vol 5 ◽

Cited By ~ 21

Author(s):

Ryan McClure ◽

Brian Tjaden ◽

Caroline Genco

Keyword(s):

Neisseria Gonorrhoeae ◽

Growth Conditions ◽

Human Pathogen

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Genetic and biochemical characterization of an exopolygalacturonase and a pectate lyase fromYersinia enterocolitica

Canadian Journal of Microbiology ◽

10.1139/w99-034 ◽

1999 ◽

Vol 45 (5) ◽

pp. 396-403 ◽

Cited By ~ 17

Author(s):

Ching-Hsing Liao ◽

Larry Revear ◽

Arland Hotchkiss ◽

Brett Savary

Keyword(s):

High Performance ◽

Biochemical Characterization ◽

Amperometric Detection ◽

Pectate Lyase ◽

Anion Exchange Chromatography ◽

Exchange Chromatography ◽

Human Pathogen ◽

Gene Encoding ◽

Reading Frame ◽

Chromatography Analysis

Yersinia enterocolitica, an invasive foodborne human pathogen, degrades polypectate by producing two depolymerizing enzymes, pectate lyase (PL) and polygalacturonase (PG). The gene encoding the PG activity, designated pehY, was located in a 3-kb genomic fragment of Y. enterocolitica ATCC 49397. The complete nucleotide sequence of this 3-kb fragment was determined and an open reading frame consisting of 1803 bp was predicted to encode a PG protein with an estimated Mrof 66 kDa and pI of 6.3. The amino acid sequence of prePG showed 59 and 43% identity to that of the exopolygalacturonase (exoPG) of Erwinia chrysanthemi and Ralstonia solanacearum, respectively. The Y. enterocolitica PG overproduced in Escherichia coli was purified to near homogeneity using perfusion cation exchange chromatography. Analysis of the PG depolymerization products by high performance anion-exchange chromatography and pulsed amperometric detection (HPAEC-PAD) revealed the exolytic nature of this enzyme. The Y. enterocolitica PL overproduced in E. coli was also partially purified and the Mrand pI were estimated to be 55 kDa and 5.2, respectively. HPAEC-PAD analysis of the PL depolymerization products indicated the endolytic nature of this enzyme. Southern hybridization analyses revealed that pehY and pel genes of Y. enterocolitica are possibly encoded in the chromosome rather than in the plasmid. Purified exopolygalacturonase (over 10 activity units) was unable to macerate plant tissues.Key words: pectinase activities, human pathogen, HPLC analysis, pehY gene.

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