Quinoproteins: enzymes containing the quinonoid cofactor pyrroloquinoline quinone, topaquinone or tryptophan-tryptophan quinone

Duine, Johannis A.

doi:10.1007/978-3-642-77200-9_10

Cited by 28 publications

(41 citation statements)

References 185 publications

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“…The results of inhibition with azide, cyanide, and o-phenanthroline are relatively consistent with what has previously been reported, but do not conclusively suggest the involvement of an MCO because these compounds may also interact with Mn. Although inhibition by these compounds is consistent with an MCO, these compounds affect the activity of other types of metalloenzymes (Hille 1994;Supuran et al 2004), and azide and cyanide also react directly with PQQ (Frank et al 1988;Duine 1991). Previous results with Erythrobacter sp.…”

Section: Discussionmentioning

confidence: 60%

In vitro studies indicate a quinone is involved in bacterial Mn(II) oxidation

Johnson

Tebo

2007

Arch Microbiol

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Manganese(II)-oxidizing bacteria play an integral role in the cycling of Mn as well as other metals and organics. Prior work with Mn(II)-oxidizing bacteria suggested that Mn(II) oxidation involves a multicopper oxidase, but whether this enzyme directly catalyzes Mn(II) oxidation is unknown. For a clearer understanding of Mn(II) oxidation, we have undertaken biochemical studies in the model marine α-proteobacterium, Erythrobacter sp. strain SD21. The optimum pH for Mn(II)-oxidizing activity was 8.0 with a specific activity of 2.5 nmol × min −1 × mg −1 and a K m = 204 µM. The activity was soluble suggesting a cytoplasmic or periplasmic protein. Mn(III) was an intermediate in the oxidation of Mn(II) and likely the primary product of enzymatic oxidation. The activity was stimulated by pyrroloquinoline quinone (PQQ), NAD + , and calcium but not by copper. In addition, PQQ rescued Pseudomonas putida MnB1 non Mn(II)-oxidizing mutants with insertions in the anthranilate synthase gene. The substrate and product of anthranilate synthase are intermediates in various quinone biosyntheses. Partially purified Mn(II) oxidase was enriched in quinones and had a UV/VIS absorption spectrum similar to a known quinone requiring enzyme but not to multicopper oxidases. These studies suggest that quinones may play an integral role in bacterial Mn(II) oxidation.

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Section: Discussionmentioning

confidence: 60%

In vitro studies indicate a quinone is involved in bacterial Mn(II) oxidation

Johnson

Tebo

2007

Arch Microbiol

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“…Consistent with this, repression of hut (and lac) expression by glucose (but not other sugars) is abolished in K. pneumoniae mutants that lack glucose dehydrogenase (104). Glucose dehydrogenase requires an unusual quinone cofactor, pyrroloquinoline quinone (PQQ), for its activity (25). Although E. coli has the gene for glucose dehydrogenase and synthesizes the apoenzyme in a regulated way (39), E. coli lacks the genes or capability for PQQ synthesis and cannot form an active glucose dehydrogenase in pure culture unless PQQ is provided in the medium (98).…”

Section: Enteric Bacteriamentioning

confidence: 99%

Regulation of the Histidine Utilization (Hut) System in Bacteria

Bender

2012

Microbiol Mol Biol Rev

123

128

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SUMMARY The ability to degrade the amino acid histidine to ammonia, glutamate, and a one-carbon compound (formate or formamide) is a property that is widely distributed among bacteria. The four or five enzymatic steps of the pathway are highly conserved, and the chemistry of the reactions displays several unusual features, including the rearrangement of a portion of the histidase polypeptide chain to yield an unusual imidazole structure at the active site and the use of a tightly bound NAD molecule as an electrophile rather than a redox-active element in urocanase. Given the importance of this amino acid, it is not surprising that the degradation of histidine is tightly regulated. The study of that regulation led to three central paradigms in bacterial regulation: catabolite repression by glucose and other carbon sources, nitrogen regulation and two-component regulators in general, and autoregulation of bacterial regulators. This review focuses on three groups of organisms for which studies are most complete: the enteric bacteria, for which the regulation is best understood; the pseudomonads, for which the chemistry is best characterized; and Bacillus subtilis , for which the regulatory mechanisms are very different from those of the Gram-negative bacteria. The Hut pathway is fundamentally a catabolic pathway that allows cells to use histidine as a source of carbon, energy, and nitrogen, but other roles for the pathway are also considered briefly here.

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“…The protons generated in the oxidation contribute directly to the trans-membrane proton motive force (PMF), which results in the uptake of exogenous amino acids and other compounds 5 . Hence, this oxidative glucose pathway might be important for the survival of enteric bacteria in aerobic, low-phosphate, aquatic environments 8 .…”

Section: Introductionmentioning

confidence: 99%

Glucose dehydrogenase of a rhizobacterial strain of Enterobacter asburiae involved in mineral phosphate solubilization shares properties and sequence homology with other members of enterobacteriaceae

Tripura

Reddy²,

Reddy³

et al. 2007

Indian J Microbiol

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Glucose dehydrogenase (GDH) of Gram-negative bacteria is a membrane bound enzyme catalyzing the oxidation of glucose to gluconic acid and is involved in the solubilization of insoluble mineral phosphate complexes. A 2.4 kb glucose dehydrogenase gene (gcd ( ( ) AT15 (gcd ( ( ::cm) and the purifi ed recomfi binant protein had a high affi nity to glucose, and oxidized fi galactose and maltose with lower affi nities. fi The enzyme was highly sensitive to heat and EDTA, and belonged to Type I, similar to GDH of E. coli.

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Quinoproteins: enzymes containing the quinonoid cofactor pyrroloquinoline quinone, topaquinone or tryptophan-tryptophan quinone

Cited by 28 publications

References 185 publications

In vitro studies indicate a quinone is involved in bacterial Mn(II) oxidation

In vitro studies indicate a quinone is involved in bacterial Mn(II) oxidation

Regulation of the Histidine Utilization (Hut) System in Bacteria

Glucose dehydrogenase of a rhizobacterial strain of Enterobacter asburiae involved in mineral phosphate solubilization shares properties and sequence homology with other members of enterobacteriaceae

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