Sequence of the mglB gene from Escherichia coli K12: Comparison of wild-type and mutant galactose chemoreceptors

Scholle, Annette; Vreemann, Jörg; Blank, Volker; Nold, Annette; Boos, Winfried; Manson, Michael D.

doi:10.1007/bf00330450

Cited by 55 publications

(32 citation statements)

References 48 publications

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“…On the basis of a high amino acid sequence identity with bacterial glucose-galactose transport and chemoreceptor MglB lipoproteins and expression of a recombinant mature lipoprotein with an apparent molecular weight of 36,000, the cloned gene from B. pilosicoli was named mglB (49). This is consistent with the recent demonstration of a putative mgl-like operon in T. pallidum (40) and MglB homologues among oral spirochetes Treponema phagedenis, T. denticola, and Treponema refringens (3).…”

Section: Discussionsupporting

confidence: 75%

Cloning and DNA Sequence Analysis of an Immunogenic Glucose-Galactose MglB Lipoprotein Homologue fromBrachyspira pilosicoli, the Agent of Colonic Spirochetosis

2000

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Colonic spirochetosis (CS) is a newly emerging infectious disease of humans and animals caused by the pathogenic spirochete Brachyspira (formerly Serpulina) pilosicoli. The purpose of this study was to characterize an antigen that was recognized by antibodies present in sera of challenge-exposed pigs. The gene encoding the antigen was identified by screening a plasmid library of human B. pilosicoli strain SP16 (ATCC 49776) genomic DNA with hyperimmune and convalescent swine sera. The predicted amino acid sequence encoded by the cloned B. pilosicoli gene had a high degree of similarity and identity to glucose-galactose MglB lipoprotein. Located 106 bp downstream of the putative mglB gene was a 3-truncated open reading frame with 73.8% similarity and 66.3% identity to mglA of Escherichia coli, suggesting a gene arrangement within an operon which is similar to those of other bacteria. A single copy of the gene was present in B. pilosicoli, and homologous sequences were widely conserved among porcine intestinal spirochetes Serpulina intermedia, Brachyspira innocens, Brachyspira murdochii, and the avian Brachyspira alvinipulli, but not in porcine Brachyspira hyodysenteriae, human Brachyspira aalborgi, and porcine Treponema succinifaciens. The deduced molecular weight of the mature MglB lipoprotein was consistent with expression by the cloned gene of a polypeptide with an apparent molecular weight of 36,000, as determined by Western blot analysis and [ 3 H]palmitate labeling. Because mucin is the principal constituent of the colonic mucus gel and consists of glycoproteins that can serve as the substrate for growth and chemotaxis of B. pilosicoli in vitro, a role for MglB in mucosal localization of the spirochete appears consistent with the pathogenesis of CS. However, the presence of homologous sequences in closely related but nonpathogenic commensal spirochetes suggests that other virulence determinants may be required for pathogenesis.Colonic spirochetosis (CS) is a newly emerging infectious disease of humans and animals caused by the pathogenic spirochete Brachyspira (formerly Serpulina) pilosicoli (6,7,9,38,56,58). Infection with B. pilosicoli or lesions consistent with CS have been recorded in a wide variety of hosts including human beings (6, 22, 56, 61, 62), nonhuman primates (8, 9, 36), pigs (2, 6, 7, 11, 13, 27, 52, 54, 55), dogs (6, 8, 10), commercial chickens, and various species of wild and zoo birds (39). The prevalence of CS among adults in the United States and Europe ranges between 4.5 and 32.2% (45). By contrast, infection with B. pilosicoli is endemic among villagers in Papua New Guinea; 93.6% of the population is infected for a calculated average duration of about 4 months (61). Porcine, canine, human, and monkey strains of B. pilosicoli are closely related and cause CS in chick and swine infection models (6,9,10,11,15,35,36,54,(57)(58)(59)(60). Similarly, laboratory mice can be colonized for up to 30 days with human, porcine, and avian B. pilosicoli strains (46). Collectively, these data suggest t...

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Section: Discussionsupporting

confidence: 75%

Cloning and DNA Sequence Analysis of an Immunogenic Glucose-Galactose MglB Lipoprotein Homologue fromBrachyspira pilosicoli, the Agent of Colonic Spirochetosis

2000

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“…Also, regions comprising residues 297 to 303 and the last 7 of the 370 residues of MBP seem to be important for maltose taxis (11 (10). The mglB551 mutation (14), which disrupts the chemotactic function of GBP while leaving its substratebinding and transport functions intact (28), introduces aspartate instead of glycine at residue 74 of GBP (34), which is in the middle of region A. The malE mutations described here do not map near region A of MBP.…”

Section: Resultsmentioning

confidence: 98%

Maltose chemoreceptor of Escherichia coli: interaction of maltose-binding protein and the tar signal transducer

1988

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The maltose chemoreceptor in Escherichia coli consists of the periplasmic maltose-binding protein (MBP) and the Tar signal transducer, which is localized in the cytoplasmic membrane. We previously isolated strains containing malE mutations that cause specific defects in the chemotactic function of MBP. Four of these mutations have now been characterized by DNA sequence analysis. Two of them replace threonine at residue 53 of MBP with isoleucine (MBP-TI53), one replaces an aspartate at residue 55 with asparagine (MBP-DN55), and the fourth replaces threonine at residue 345 with isoleucine (MBP-TI345). The chemotactic defects of MBP-TI53 and MBP-DN55, but not of MBP-TI345, are suppressed by mutations in the tar gene. Of the tar mutations, the most effective suppressor (isolated independently three times) replaces Arg-73 of Tar with tryptophan. Two other tar mutations that disrupt the aspartate chemoreceptor function of Tar also suppress the maltose taxis defects associated with MBP-TI53 and MBP-DN55. One of these mutations introduces glutamine at residue 73 of Tar, the other replaces arginine at residue 69 of Tar with cysteine. These results suggest that regions of MBP that include residues 53 to 55 and residue 345 are important for the interaction with Tar. In turn, arginines at residues 69 and 73 of Tar must be involved in the recognition of maltose-bound MBP and/or in the production of the attractant signal generated by Tar in response to maltose-bound MBP.

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“…Thus, for growth on glucose the system has to be induced by the nonmetabolizable D-fUcose, or galR mutants, which express galP constitutively, have to be used (7). The other transport system capable of recognizing glucose is the galactose-binding protein-dependent transport system for galactose and ,8-methyl galactoside, encoded by mgl (60,64). This system is highly sensitive to catabolite repression (4) and can be expressed only when glucose cannot enter via a PTS-dependent route.…”

Section: Discussionmentioning

confidence: 99%

The malX malY operon of Escherichia coli encodes a novel enzyme II of the phosphotransferase system recognizing glucose and maltose and an enzyme abolishing the endogenous induction of the maltose system

Reidl

Boos

1991

J Bacteriol

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Mutants lacking MalK, a subunit of the binding protein-dependent maltose-maltodextrin transport system, constitutively express the maltose genes. A second site mutation in mall abolishes the constitutive expression. glucose in a ptsM ptsG glk mutant, and the plasmid-encoded MalY alone was sufficient to abolish the constitutivity of the mal genes in a malK mutant. The overexpressio'n of malY in a strain that is wild type with respect to the maltose genes strongly interferes with growth on maltose. This is not the case in a malT(Con) strain that expresses the mal genes constitutively. We conclude that malY encodes an enzyme that degrades the inducer of the maltose system or prevents its synthesis.

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Sequence of the mglB gene from Escherichia coli K12: Comparison of wild-type and mutant galactose chemoreceptors

Cited by 55 publications

References 48 publications

Cloning and DNA Sequence Analysis of an Immunogenic Glucose-Galactose MglB Lipoprotein Homologue fromBrachyspira pilosicoli, the Agent of Colonic Spirochetosis

Cloning and DNA Sequence Analysis of an Immunogenic Glucose-Galactose MglB Lipoprotein Homologue fromBrachyspira pilosicoli, the Agent of Colonic Spirochetosis

Maltose chemoreceptor of Escherichia coli: interaction of maltose-binding protein and the tar signal transducer

The malX malY operon of Escherichia coli encodes a novel enzyme II of the phosphotransferase system recognizing glucose and maltose and an enzyme abolishing the endogenous induction of the maltose system

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