<i>Helicobacter pylori cad</i>A encodes an essential Cd(II)–Zn(II)–Co(II) resistance factor influencing urease activity

Herrmann, Lutz; Schwan, Dorothee; Garner, Rachel M.; Mobley, Harry L. T.; Haas, Rainer; Schäfer, Klaus; Melchers, Klaus

doi:10.1046/j.1365-2958.1999.01496.x

Cited by 44 publications

(39 citation statements)

References 64 publications

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“…Instead we detected cadA which is mostly found in Gram-positive bacteria [50][51][52][53]. The genome sequences of several Gram-negative bacteria have revealed homologs of cadA [54,55] and there are some reports of cadA-encoded cadmium resistance being identified in some Pseudomonas species [56,57]. The cadA gene detected in this study is believed to be chromosomally located since southern hybridisation did not detect the presence of the gene on the plasmids in any of the isolates tested.…”

Section: Discussioncontrasting

confidence: 52%

Resistance Determinants of Pseudomonas Species from Aquaculture in Australia

Ndi¹

2012

J Aquac Res Development

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Section: Discussioncontrasting

confidence: 52%

Resistance Determinants of Pseudomonas Species from Aquaculture in Australia

Ndi¹

2012

J Aquac Res Development

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“…2). Zinc is essential for the activity of several enzymes in H. pylori, such as a metalloprotease (32) or ATPase (9). The metalloprotease is a 200-kDa outer membrane-associated enzyme with endoprotease activity for casein (32).…”

Section: Discussionmentioning

confidence: 99%

“…The metalloprotease is a 200-kDa outer membrane-associated enzyme with endoprotease activity for casein (32). The ATPase CadA is an ion pump with specificity for zinc, cobalt, and cadmium and has a possible role in modulating urease activity (9).…”

Section: Discussionmentioning

confidence: 99%

Helicobacter pylori Growth and Urease Detection in the Chemically Defined Medium Ham's F-12 Nutrient Mixture

2001

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Obstacles continue to hinder in vitro studies of the gastric human pathogen Helicobacter pylori, including difficulty culturing the organism in the absence of serum or blood, rapid loss of viability following exponential growth due to autolysis, and the necessity for using high starting inocula. We demonstrate that H. pylori grows in the chemically defined broth medium Ham's F-12 nutrient mixture (F-12) in the absence of fetal bovine serum (FBS); this represents a breakthrough for studies in which serum components or proteins interfere with interpretation of results. Cultures can be continually passaged in fresh, FBS-free F-12 medium at an initial inoculum of only ϳ10 3 CFU/ml. All H. pylori strains (n ‫؍‬ 21), including fresh clinical isolates, grew in serum-free F-12. H. pylori grew poorly in the related medium, F-10, unless additional zinc was supplied. Enhanced growth of H. pylori in F-12 broth was obtained by addition of bovine serum albumin (BSA) (1 mg/ml), ␤-cyclodextrin (200 g/ml), or cholesterol (50 g/ml). H. pylori also grew in several simplified versions of F-12 broth lacking glucose and most vitamins but containing hypoxanthine, pyruvate, and all 20 amino acids. On F-12 medium solidified with agar, H. pylori only grew when BSA (98% pure; 1 mg/ml), cholesterol (50 g/ml), ␤-cyclodextrin (200 g/ml), or FBS (2 to 4%) was added; addition of urea and phenol allowed colorimetric detection of urease activity. Thus, F-12 agar plus cholesterol or ␤-cyclodextrin represents the first transparent chemically defined agar and the first urease indicator agar for H. pylori. Several lines of evidence suggested that BSA itself is not responsible for H. pylori growth enhancement in F-12 containing BSA or FBS. Taken together, these innovations represent significant advances in the cultivation and recovery of H. pylori using chemically defined media. Use of F-12 or its derivatives may lead to improved understanding of H. pylori metabolism, virulence factors, and transmission, and result in improved recovery and identification of H. pylori from clinical specimens.

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“…Closely related P-type ATPases specific for Cu 2ϩ can function with either inwardly or outwardly directed polarity, depending on the system. Bacterial Cd , and Pb 2ϩ ) as well as Cd 2ϩ (7,49,80). Anion transport can be driven by ATP hydrolysis either via ArsAB systems (TC 3.A.4), which catalyze efflux, or via ABC systems (TC 3.A.1), which catalyze uptake.…”

Section: Secondary Carriersmentioning

confidence: 99%

A Functional-Phylogenetic Classification System for Transmembrane Solute Transporters

Saier

2000

Microbiol Mol Biol Rev

745

642

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SUMMARY A comprehensive classification system for transmembrane molecular transporters has been developed and recently approved by the transport panel of the nomenclature committee of the International Union of Biochemistry and Molecular Biology. This system is based on (i) transporter class and subclass (mode of transport and energy coupling mechanism), (ii) protein phylogenetic family and subfamily, and (iii) substrate specificity. Almost all of the more than 250 identified families of transporters include members that function exclusively in transport. Channels (115 families), secondary active transporters (uniporters, symporters, and antiporters) (78 families), primary active transporters (23 families), group translocators (6 families), and transport proteins of ill-defined function or of unknown mechanism (51 families) constitute distinct categories. Transport mode and energy coupling prove to be relatively immutable characteristics and therefore provide primary bases for classification. Phylogenetic grouping reflects structure, function, mechanism, and often substrate specificity and therefore provides a reliable secondary basis for classification. Substrate specificity and polarity of transport prove to be more readily altered during evolutionary history and therefore provide a tertiary basis for classification. With very few exceptions, a phylogenetic family of transporters includes members that function by a single transport mode and energy coupling mechanism, although a variety of substrates may be transported, sometimes with either inwardly or outwardly directed polarity. In this review, I provide cross-referencing of well-characterized constituent transporters according to (i) transport mode, (ii) energy coupling mechanism, (iii) phylogenetic grouping, and (iv) substrates transported. The structural features and distribution of recognized family members throughout the living world are also evaluated. The tabulations should facilitate familial and functional assignments of newly sequenced transport proteins that will result from future genome sequencing projects.

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Helicobacter pylori cadA encodes an essential Cd(II)–Zn(II)–Co(II) resistance factor influencing urease activity

Cited by 44 publications

References 64 publications

Resistance Determinants of Pseudomonas Species from Aquaculture in Australia

Resistance Determinants of Pseudomonas Species from Aquaculture in Australia

Helicobacter pylori Growth and Urease Detection in the Chemically Defined Medium Ham's F-12 Nutrient Mixture

A Functional-Phylogenetic Classification System for Transmembrane Solute Transporters

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