A Cytochemical Localization of Reductive Sites in a Gram-Positive Bacterium

Iterson, Woutera van; Leene, W.

doi:10.1083/jcb.20.3.361

Cited by 109 publications

(61 citation statements)

References 44 publications

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“…The increase in haem content which accompanies this cytological modification provides evidence that mesosomes can function as areas of concentrated respiratory activity; this is in accord with the cytochemical observations of van Iterson & Leene (1964) in BaciZlus subtilis. Further, one of us (J. S. P.) has found that phosphate limitation similarly results in the proliferation of small, peripheral mesosomes.…”

Section: Discussionsupporting

confidence: 79%

The Internal Membranes of Caulobacter Crescentus

Cohen-Bazire¹,

Kunisawa²,

Poindexter³

1966

Journal of General Microbiology

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SUMMARYThe intracytoplasmic membranous structures previously observed in various caulobacter species by electron microscopy of thin sections were studied further by electron microscopy of whole organisms of Caulobacter crescentus negatively stained with phosphotungstate. The large, complex mesosomes are intrusions of the cell membrane. They appeared, from their central location in dividing cells, to play a role in division. Smaller and less involuted intrusions of the membrane became abundant in oxygenlimited cells, which also had an abnormally high content of haem pigments. These smaller intrusions may therefore be a structural reflexion of an increased content in the membrane of components of the respiratory electron transport system. The membranous organelle which occurred a t the site of stalk formation and appeared to be connected with the membranous core of the stalk was not penetrated by phosphotungstate, and therefore had an organization different from that of the mesosome.

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Section: Discussionsupporting

confidence: 79%

The Internal Membranes of Caulobacter Crescentus

Cohen-Bazire¹,

Kunisawa²,

Poindexter³

1966

Journal of General Microbiology

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“…Bacterial cells resistant to tellurite often turn black when grown in liquid or solid media amended with K 2 TeO 3 , a phenotype that is also displayed by sensitive bacteria growing in media supplemented with sub-lethal concentrations of tellurite [18]. These deposits are of an insoluble material localized to specific subcellular compartments [19], [20], which X-ray diffraction studies have shown to be the less toxic, free metal, tellurium (Te°) [21], [22].…”

Section: Introductionmentioning

confidence: 99%

Catalases Are NAD(P)H-Dependent Tellurite Reductases

et al. 2006

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Reactive oxygen species damage intracellular targets and are implicated in cancer, genetic disease, mutagenesis, and aging. Catalases are among the key enzymatic defenses against one of the most physiologically abundant reactive oxygen species, hydrogen peroxide. The well-studied, heme-dependent catalases accelerate the rate of the dismutation of peroxide to molecular oxygen and water with near kinetic perfection. Many catalases also bind the cofactors NADPH and NADH tenaciously, but, surprisingly, NAD(P)H is not required for their dismutase activity. Although NAD(P)H protects bovine catalase against oxidative damage by its peroxide substrate, the catalytic role of the nicotinamide cofactor in the function of this enzyme has remained a biochemical mystery to date. Anions formed by heavy metal oxides are among the most highly reactive, natural oxidizing agents. Here, we show that a natural isolate of Staphylococcus epidermidis resistant to tellurite detoxifies this anion thanks to a novel activity of its catalase, and that a subset of both bacterial and mammalian catalases carry out the NAD(P)H-dependent reduction of soluble tellurite ion (TeO3 2−) to the less toxic, insoluble metal, tellurium (Te°), in vitro. An Escherichia coli mutant defective in the KatG catalase/peroxidase is sensitive to tellurite, and expression of the S. epidermidis catalase gene in a heterologous E. coli host confers increased resistance to tellurite as well as to hydrogen peroxide in vivo, arguing that S. epidermidis catalase provides a physiological line of defense against both of these strong oxidizing agents. Kinetic studies reveal that bovine catalase reduces tellurite with a low Michaelis-Menten constant, a result suggesting that tellurite is among the natural substrates of this enzyme. The reduction of tellurite by bovine catalase occurs at the expense of producing the highly reactive superoxide radical.

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“…Many microorganisms produce black intracellular deposits when grown in media supplemented with potassium tellurite (14,15,23,25,(28)(29)(30)(31). Even sensitive bacteria are capable of forming jet-black colonies when growing at subinhibitory tellurite concentrations (25).…”

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confidence: 99%

Purification and biochemical characterization of tellurite-reducing activities from Thermus thermophilus HB8

et al. 1988

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Cell-free extracts of Thermus thermophilus HB8 catalyze the in vitro, NADH-dependent reduction of potassium teilurite (K2TeO3). Three different protein fractions with tellurite-reducing activities were identified.Two exhibited high molecular weight and were composed of at least two different polypeptides. The protein in the third fraction was purified to homogeneity and had a single polypeptide chain of 53 to 54 kilodaltons, with an isoelectric point of 8.1. Each enzyme was thermostable, the temperature optimum was 75°C, and 30 mM NaCl, 1.5 M urea, or 0.004% sodium dodecyl sulfate caused 50% inhibition of the enzymes. However, 2% Triton X-100 did not have an inhibitory effect. The enzymes were also able to catalyze the reduction of sodium selenite and sodium sulfite in vitro. NADH was replaceable by NADPH. Divalent cations, such as Ca2' and

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A Cytochemical Localization of Reductive Sites in a Gram-Positive Bacterium

Cited by 109 publications

References 44 publications

The Internal Membranes of Caulobacter Crescentus

The Internal Membranes of Caulobacter Crescentus

Catalases Are NAD(P)H-Dependent Tellurite Reductases

Purification and biochemical characterization of tellurite-reducing activities from Thermus thermophilus HB8

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