Identification of tandem genes involved in lipooligosaccharide expression by Haemophilus ducreyi

Stevens, Marla K.; Klesney-Tait, Julia; Lumbley, Sheryl R.; Walters, Kathie–Anne; Joffe, Ari; Radolf, Justin D.; Hansen, Eric J.

doi:10.1128/iai.65.2.651-660.1997

Cited by 24 publications

(28 citation statements)

References 69 publications

(54 reference statements)

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“…Secondary structure elements for HAP1 are shown as blue cylinders (α-helix) and magenta arrows (β-strands). The sequences are HAP1 (Human, 44-318; M99703; Robson and Hickson, 1991), EXOIII (Escherichia coli, 1-268; D90818) L31 (Haemophilus ducreyi, 1-267; U58147; Stevens et al, 1997), ARP (Arabidopsis thaliana 249-527; X76912; Babiychuk et al, 1994), Ddape (Dictyostelium discoideum 86-361; U31631; Freeland et al, 1996), EXOA (Streptococcus pneumoniae 1-275; J04234; Puyet et al, 1989), Rrp1 (Drosophila melanogaster 408-679; M62472; Sander et al, 1991), L1 (Human 1-246; U09116; Holmes et al, 1994) and DNase I (Bovine 1-260; M60606; Worrall and Connolly, 1990). overall sequence of L1 EN is more similar to that of HAP1 (25% identity) and EXOIII (23% identity) than to DNase I (14% identity), L1 EN has no equivalent sequences to two (α8 and α11) of the three helical loop regions which are present in HAP1 and EXOIII, but are absent in DNase I (Figure 4).…”

Section: Comparison Of Hap1 With Exoiii and Dnase Imentioning

confidence: 99%

The crystal structure of the human DNA repair endonuclease HAP1 suggests the recognition of extra-helical deoxyribose at DNA abasic sites

Gorman¹,

Moréra²,

et al. 1997

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The structure of the major human apurinic/ apyrimidinic endonuclease (HAP1) has been solved at 2.2 Å resolution. The enzyme consists of two symmetrically related domains of similar topology and has significant structural similarity to both bovine DNase I and its Escherichia coli homologue exonuclease III (EXOIII). A structural comparison of these enzymes reveals three loop regions specific to HAP1 and EXOIII. These loop regions apparently act in DNA abasic site (AP) recognition and cleavage since DNase I, which lacks these loops, correspondingly lacks AP site specificity. The HAP1 structure furthermore suggests a mechanism for AP site binding which involves the recognition of the deoxyribose moiety in an extrahelical conformation, rather than a 'flipped-out' base opposite the AP site.

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Section: Comparison Of Hap1 With Exoiii and Dnase Imentioning

confidence: 99%

The crystal structure of the human DNA repair endonuclease HAP1 suggests the recognition of extra-helical deoxyribose at DNA abasic sites

Gorman¹,

Moréra²,

et al. 1997

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“…MAb and colony blot radioimmunoassay. Monoclonal antibody (MAb) 3E6 is specific for a surface-exposed epitope in H. ducreyi 35000 LOS and has been (60). The colony blot radioimmunoassay was performed as described previously (60) with MAb 3E6 culture supernatant as the source of the primary antibody.…”

Section: Methodsmentioning

confidence: 99%

“…Recovered organisms were subcultured onto CA supplemented with appropriate antimicrobial compounds to confirm the presence of the relevant antimicrobial resistance markers and were also tested by a colony blot radioimmunoassay with MAb 3E6 to confirm the LOS phenotype. Statistical analyses were performed as described previously (60,61).…”

Section: Analysis Of H Ducreyi Los and E Coli Lpsmentioning

confidence: 99%

“…Only recently have attempts been made to address the possible involvement of the oligosaccharide portion of H. ducreyi LOS in the pathogenesis of chancroid. Mutants defective in the expression of LOS have been described (9,21,60), and while at least four different genes whose encoded protein products are directly or indirectly involved in H. ducreyi LOS expression have been cloned and sequenced (21,60,66), only one of these has been tested by mutant analysis in relevant in vitro and in vivo systems. An H. ducreyi mutant defective in the expression of an RfaK homolog was shown to exhibit a reduced ability to attach to and invade human keratinocytes in vitro (21).…”

mentioning

confidence: 99%

“…An H. ducreyi mutant defective in the expression of an RfaK homolog was shown to exhibit a reduced ability to attach to and invade human keratinocytes in vitro (21). Virulence testing of an independently constructed H. ducreyi rfaK (i.e., lbgB) mutant in the temperature-dependent rabbit model for experimental chancroid (49) yielded equivocal results (60).…”

mentioning

confidence: 99%

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Involvement of the Haemophilus ducreyi gmhA Gene Product in Lipooligosaccharide Expression and Virulence

Bauer

Stevens²,

Hansen³

1998

Infect. Immun.

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The lipooligosaccharide (LOS) present in the outer membrane of Haemophilus ducreyi is likely a virulence factor for this sexually transmitted pathogen. An open reading frame in H. ducreyi 35000 was found to encode a predicted protein that had 87% identity with the protein product of the gmhA (isn) gene of Haemophilus influenzae. In H. influenzae type b, inactivation of the gmhA gene caused the synthesis of a significantly truncated LOS which possessed only lipid A and a single 2-keto-3-deoxyoctulosonic acid molecule (. 178:396-402, 1996). The H. ducreyi gmhA gene was able to complement a gmhA-deficient Escherichia coli strain, a result which confirmed the identity of this gene. When the gmhA gene of H. ducreyi was inactivated by insertion of a cat cartridge, the resultant H. ducreyi gmhA mutant, 35000.252, expressed a LOS that migrated much faster than wild-type LOS in sodium dodecyl sulfatepolyacrylamide gel electrophoresis. When the wild-type H. ducreyi strain and its isogenic gmhA mutant were used in the temperature-dependent rabbit model for dermal lesion production by H. ducreyi, the gmhA mutant was found to be substantially less virulent than the wild-type parent strain. The H. ducreyi gmhA gene was amplified by PCR from the H. ducreyi chromosome and cloned into the pLS88 vector. When the H. ducreyi gmhA gene was present in trans in gmhA mutant 35000.252, expression of the gmhA gene product restored the virulence of this mutant to wild-type levels. These results indicate that the gmhA gene product of H. ducreyi is essential for the expression of wild-type LOS by this pathogen.

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Proposed second class of Haemophilus ducreyi strains show altered protein and lipooligosaccharide profiles

Post

Gibson

2007

Proteomics

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Haemophilus ducreyi is the etiologic agent of chancroid, a sexually transmitted genital ulcer disease. Previously we have shown that the protein profiles and lipooligosaccharide (LOS) structures from various strains of H. ducreyi are generally well conserved. Previous studies have demonstrated that at least one strain, 33921, has a variant protein profile and LOS structure. In this study, both the whole cell lysate and the membrane proteins from strain 33921 were further examined and compared to the prototypical strain 35000HP by 2-DE and by the 16-BAC (benzyldimethyl-n-hexadecylammonium chloride)/SDS-PAGE two-detergent system, respectively. These comparisons demonstrated that a number of the proteins that could be identified from both strains had altered positions on the gels, both in their apparent molecular weight and pI values. Strain 33921 has been suggested to be a member of a second class of strains, termed class II strains. In this study, the proteomic profiles and the LOS structures from the five potential class II strains were examined and found to be similar to strain 33921.

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Identification of tandem genes involved in lipooligosaccharide expression by Haemophilus ducreyi

Abstract: A transposon insertion mutant of Haemophilus ducreyi 35000 possessing a truncated lipooligosaccharide (LOS) failed to bind the LOS-specific monoclonal antibody 3E6 (M. K.

Cited by 24 publications

References 69 publications

The crystal structure of the human DNA repair endonuclease HAP1 suggests the recognition of extra-helical deoxyribose at DNA abasic sites

The crystal structure of the human DNA repair endonuclease HAP1 suggests the recognition of extra-helical deoxyribose at DNA abasic sites

Involvement of the Haemophilus ducreyi gmhA Gene Product in Lipooligosaccharide Expression and Virulence

Proposed second class of Haemophilus ducreyi strains show altered protein and lipooligosaccharide profiles

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