Catabolism in Mollicutes

Milès, Roger

doi:10.1099/00221287-138-9-1773

Cited by 73 publications

(49 citation statements)

References 79 publications

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“…In contrast, the enzyme complement for the pentose-phosphate pathway is incomplete. Since M. pneumoniae lacks enzymes for the tricarboxylic acid cycle, quinones and cytochromes, ATP generation is restricted to substrate-level phosphorylation (Razin et al, 1998 ;Himmelreich et al, 1996 ;Miles, 1992). In addition to carbohydrates, M. pneumoniae can probably catabolize arginine, yielding ammonia and ATP (Himmelreich et al, 1996) K. Steinhauer and others regulatory proteins.…”

Section: Introductionmentioning

confidence: 99%

A novel mode of control of Mycoplasma pneumoniae HPr kinase/phosphatase activity reflects its parasitic lifestyle

et al. 2002

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Among the few regulatory proteins encoded by Mycoplasma pneumoniae is HPr kinase/phosphatase (HPrK/P), the key regulator of carbon metabolism in low-GC Gram-positive bacteria. The corresponding gene, hprK, and the gene encoding the target protein HPr, ptsH, were overexpressed. In vitro analysis of the purified proteins confirmed ATP-dependent phosphorylation of HPr by HPrK/P. In contrast to HPrK/P of Bacillus subtilis, which is by default a phosphatase and needs high ATP concentrations for kinase activity, the M. pneumoniae enzyme exhibits kinase activity at very low ATP concentrations and depends on P i for phosphatase activity. This inverted control of enzymic activity may result from the adaptation to very different ecological niches. While the standard activities of HPrK/P from M. pneumoniae and other Grampositive bacteria differ, they are both modulated by the concentration of ATP, P i and glycolytic intermediates. Site-directed mutagenesis of a potential ATPbinding site and of the HPrK/P signature sequence resulted in four different activity classes : (i) inactive proteins, (ii) enzymes with reduced kinase and phosphatase activities, (iii) enzymes that had lost phosphatase, but not kinase activity, and (iv) enzymes that exhibited increased phosphatase activity.

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Section: Introductionmentioning

confidence: 99%

A novel mode of control of Mycoplasma pneumoniae HPr kinase/phosphatase activity reflects its parasitic lifestyle

et al. 2002

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“…The ability to ferment glucose with the production of acid must be assessed (Aluotto et al, 1970;Edward & Moore, 1975;Razin & Cirillo, 1983). This test is especially critical with Mycoplasma species because, in this genus, glucose may or may not serve as a primary energy source (Miles, 1992;Pollack, 1992).…”

Section: (Iii) Correlation With Phenotypementioning

confidence: 99%

“…Mollicutes have diverse metabolic pathways (McElwain et al, 1988;Pollack et al, 1989Pollack et al, , 1996bPollack et al, , 1997Miles, 1992;Pollack, 1992), but the implementation of tests reflecting comparative metabolism of mollicutes has posed many challenges . Improvements in test protocols (Miles & Nicholas, 1998) may now make it possible to utilize certain metabolic characterizations more fully in mollicute taxonomy.…”

Section: (Iii) Correlation With Phenotypementioning

confidence: 99%

Revised minimal standards for description of new species of the class Mollicutes (division Tenericutes)

Brown

Whitcomb

Bradbury

2007

International Journal of Systematic and Evolutionary Microbiology

138

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Minimal standards for novel species of the class Mollicutes (trivial term, mollicutes), last published in 1995, require revision. The International Committee on Systematics of Prokaryotes Subcommittee on the Taxonomy of Mollicutes proposes herein revised standards that reflect recent advances in molecular systematics and the species concept for prokaryotes. The mandatory requirements are: (i) deposition of the type strain into two recognized culture collections, preferably located in different countries; (ii) deposition of the 16S rRNA gene sequence into a public database, and a phylogenetic analysis of the relationships among the 16S rRNA gene sequences of the novel species and its neighbours; (iii) deposition of antiserum against the type strain into a recognized collection; (iv) demonstration, by using the combination of 16S rRNA gene sequence analyses, serological analyses and supplementary phenotypic data, that the type strain differs significantly from all previously named species; and (v) assignment to an order, a family and a genus in the class, with an appropriate specific epithet. The 16S rRNA gene sequence provides the primary basis for assignment to hierarchical rank, and may also constitute evidence of species novelty, but serological and supplementary phenotypic data must be presented to substantiate this. Serological methods have been documented to be congruent with DNA-DNA hybridization data and with 16S rRNA gene placements. The novel species must be tested serologically to the greatest extent that the investigators deem feasible against all neighbouring species whose 16S rRNA gene sequences show .0.94 similarity. The investigator is responsible for justifying which characters are most meaningful for assignment to the part of the mollicute phylogenetic tree in which a novel species is located, and for providing the means by which novel species can be identified by other investigators.

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“…The arginine dihydrolase pathway, widely distributed in prokaryotes, is a major pathway in many nonfermentative mollicutes acting as a source of energy and perhaps carbon and/or nitrogen (Barile e t al., 1966;Miles, 1992). The enzymes of the pathway include arginine deiminase, which catalyses the irreversible conversion of arginine into citrulline and ammonia ; ornithine carbamoyltransferase, which catalyses the phosphorolysis of citrulline yielding ornithine and carbamoylphosphate ; and carbamate kinase, which converts carbamoylphosphate into CO, and NH, with concomitant phosphorylation of ADP to ATP (Cunnin e t al., 1986).…”

Section: Introductionmentioning

confidence: 99%

An arginine/ornithine exchange system in Spiroplasma melliferum

1995

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University-H ad assa h Medical School, POB 12272, Jerusalem 91 120, Israel Spiroplasma me//ifemm cells utilize arginine via the arginine dihydrolase pathway. L-Arginine uptake by intact cells was a saturable process both as a function of time and arginine concentration (Km = 40 pM). Uptake was not affected by pH in the range pH 59-89, or by Atrulline, o-arginine, L-histidine or L-canavanine at concentrations tenfold higher than that of L-arginine. In contrast, L-arginine uptake was markedly inhibited by L-omithine and partially inhibited by dysine. Uptake was neither affected by protonophores nor by cation ionophores, but was inhibited by protease treatment or by the sulfhydryl reagents plchloromercuribenzoate or N-ethylmaleimide. Sealed membrane vesicles prepared by fusing isolated S. mellihmm membranes with asolectin-cholesterol vesicles catalysed a rapid exchange (ti = 1 min) between arginine and ornithine. Exchange did not require ATP and could be demonstrated in both directions, i.e. with either arginine or ornithine trapped within vesicles. These observations suggest that the driving forces for arginine uptake by whole cells are the concentration gradients of arginine and ornithine formed by arginine metabolism.

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Catabolism in Mollicutes

Cited by 73 publications

References 79 publications

A novel mode of control of Mycoplasma pneumoniae HPr kinase/phosphatase activity reflects its parasitic lifestyle

A novel mode of control of Mycoplasma pneumoniae HPr kinase/phosphatase activity reflects its parasitic lifestyle

Revised minimal standards for description of new species of the class Mollicutes (division Tenericutes)

An arginine/ornithine exchange system in Spiroplasma melliferum

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