Characterization of a Hemoglobin Protease Secreted by the Pathogenic <i>Escherichia coli</i> Strain EB1

Otto, Ben R.; Dooren, Silvy J.M. van; Nuijens, Jan H.; Luirink, Joen; Oudega, Bauke

doi:10.1084/jem.188.6.1091

Cited by 132 publications

(179 citation statements)

References 48 publications

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“…Multiple iron-uptake systems, such as enterobactin, aerobactin and salmochelin, and the fungal siderophores ferrichrome and coprogen, have indeed been found in other E. coli strains (Otto et al, 1998). Besides these systems, yet another system encoding yersiniabactin (Ybt) siderophore synthesis and uptake appears to be present in the A0 34/86 strain, as detected here by the sequences of several irp and ybt genes.…”

Section: Resultsmentioning

confidence: 73%

Characterization of the flexible genome complement of the commensal Escherichia coli strain A0 34/86 (O83 : K24 : H31)

et al. 2005

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Colonization by the commensal Escherichia coli strain A0 34/86 (O83 : K24 : H31) has proved to be safe and efficient in the prophylaxis and treatment of nosocomial infections and diarrhoea of preterm and newborn infants in Czech paediatric clinics over the past three decades. In searching for traits contributing to this beneficial effect related to the gut colonization capacity of the strain, the authors have analysed its genome by DNA-DNA hybridization to E. coli K-12 (MG1655) genomic DNA arrays and to 'Pathoarrays', as well as by multiplex PCR, bacterial artificial chromosome (BAC) library cloning and shotgun sequencing. Four hundred and ten E. coli K-12 ORFs were absent from A0 34/86, while 72 out of 456 genes associated with pathogenicity islands of E. coli and Shigella were also detected in E. coli A0 34/86. Furthermore, extraintestinal pathogenic E. coli-related genes involved in iron uptake and adhesion were detected by multiplex PCR, and genes encoding the HlyA and cytotoxic necrotizing factor toxins, together with 21 genes of the uropathogenic E. coli 536 pathogenicity island II, were identified by analysis of 2304 shotgun and 1344 BAC clone sequences of A0 34/86 DNA. Multiple sequence comparisons identified 31 kb of DNA specific for E. coli A0 34/86; some of the genes carried by this DNA may prove to be implicated in the colonization capacity of the strain, enabling it to outcompete pathogens. Among 100 examined BAC clones roughly covering the A0 34/86 genome, one reproducibly conferred on the laboratory strain DH10B an enhanced capacity to persist in the intestine of newborn piglets. Sequencing revealed that this BAC clone carried gene clusters encoding gluconate and mannonate metabolism, adhesion (fim), invasion (ibe) and restriction/modification functions. Hence, the genome of this clinically safe and highly efficient colonizer strain appears to harbour many 'virulence-associated' genes. These results highlight the thin line between bacterial 'virulence' and 'fitness' or 'colonization' factors, and question the definition of enterobacterial virulence factors.Abbreviations: BAC, bacterial artificial chromosome; CNF, cytotoxic necrotizing factor; EHEC, enterohaemorrhagic Escherichia coli; ExPEC, extraintestinal pathogenic Escherichia coli; HPI, high-pathogenicity island; IPEC, intestinal pathogenic Escherichia coli; PAI, pathogenicity island; UPEC, uropathogenic Escherichia coli.The GenBank/EMBL/DDBJ accession number for the sequence of the completely sequenced BAC insert (C4/1) is AJ829704.A list of non-detectable ORFs of E. coli strain MG1655 in strain Colinfant in the order in which the ORFs appear in the MG1655 chromosome, together with a list of detectable virulence-associated or PAI-localized genes of pathogenic E. coli may be found in Supplementary Table S1 with the online version of this paper at http://mic.sgmjournals.org. A list of genes of the flexible E. coli genome complement identified in E. coli strain A0 34/86 by the combination of DNA array hybridization, Multiplex PCR and partial gen...

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Section: Resultsmentioning

confidence: 73%

Characterization of the flexible genome complement of the commensal Escherichia coli strain A0 34/86 (O83 : K24 : H31)

et al. 2005

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“…It has recently been shown that pathogenic Escherichia coli strain EB1 can secrete a serine proteinase that is able to bind Hb, degrade it, and capture the released heme (35). So far, no regulatory role has been proposed for heme in this case.…”

Section: Discussionmentioning

confidence: 99%

A Heme-binding Aspartic Proteinase from the Eggs of the Hard TickBoophilus microplus

Sorgine

Logullo

Zingali

et al. 2000

Journal of Biological Chemistry

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An aspartic proteinase that binds heme with a 1:1 stoichiometry was isolated and cloned from the eggs of the cattle tick Boophilus microplus. This proteinase, herein named THAP (tick heme-binding aspartic proteinase) showed pepstatin-sensitive hydrolytic activity against several peptide and protein substrates. Although hemoglobin was a good substrate for THAP, low proteolytic activity was observed against globin devoid of the heme prosthetic group. Hydrolysis of globin by THAP increased as increasing amounts of heme were added to globin, with maximum activation at a heme-toglobin 1:1 ratio. Further additions of heme to the reaction medium inhibited proteolysis, back to a level similar to that observed against globin alone. The addition of heme did not change THAP activity toward a synthetic peptide or against ribonuclease, a non-hemeprotein substrate. The major storage protein of tick eggs, vitellin (VT), the probable physiological substrate of THAP, is a hemeprotein. Hydrolysis of VT by THAP was also inhibited by the addition of heme to the incubation media. Taken together, our results suggest that THAP uses heme bound to VT as a docking site to increase specificity and regulate VT degradation according to heme availability.

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“…5 Two well-studied examples are hemoglobin protease (Hbp), a serine protease involved in iron scavenging for the human pathogen E. coli EB1, 13 and plasmid-encoded toxin (Pet) from E. coli 042, a pathogenic strain that causes diarrhea. 14 The crystal structure of the Pet passenger domain has not been solved, but Pet and Hbp passenger domains share 26% sequence identity plus 43% sequence similarity.…”

Section: Introductionmentioning

confidence: 99%

A conserved stable core structure in the passenger domain β‐helix of autotransporter virulence proteins

Renn

Clark

2008

Biopolymers

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In Gram‐negative bacteria, a wide variety of virulence factors are secreted via the autotransporter (AT) pathway. Intriguingly, there is no significant concentration of ATP in the periplasm, nor a proton gradient across the OM, so the energetic origin of efficient secretion of AT proteins is unknown. More than 97% of AT proteins are predicted to contain right‐handed parallel β‐helical structure, and the three crystal structures available for AT passenger domains each contain a long right‐handed parallel β‐helix. Previous studies have shown that pertactin, an AT from Bordetella pertussis, exhibits three‐state folding and has a C‐terminal stable core structure. Here, we show that Pet, an unrelated AT from Escherichia coli, also exhibits three‐state unfolding and also has a stable core structure. Deletion mutants, mass spectrometry, and N‐terminal sequencing demonstrate that the Pet stable core is also located near the C‐terminus of the passenger domain. Moreover, sequence analysis suggests that three‐state folding and a C‐terminal stable core structure could be important general features of the biogenesis of AT proteins in vivo. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 420–427, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

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Characterization of a Hemoglobin Protease Secreted by the Pathogenic Escherichia coli Strain EB1

Cited by 132 publications

References 48 publications

Characterization of the flexible genome complement of the commensal Escherichia coli strain A0 34/86 (O83 : K24 : H31)

Characterization of the flexible genome complement of the commensal Escherichia coli strain A0 34/86 (O83 : K24 : H31)

A Heme-binding Aspartic Proteinase from the Eggs of the Hard TickBoophilus microplus

A conserved stable core structure in the passenger domain β‐helix of autotransporter virulence proteins

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