Mycoplasma pneumoniae Mpn133 is a cytotoxic nuclease with a glutamic acid-, lysine- and serine-rich region essential for binding and internalization but not enzymatic activity

Somarajan, Sudha R.; Kannan, Thirumalai R; Baseman, Joel B.

doi:10.1111/j.1462-5822.2010.01513.x

Cited by 42 publications

(47 citation statements)

References 38 publications

(45 reference statements)

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“…Indeed, MPN133 seems to have a dual function: in addition to its role in glycerol transport, it also has a nuclease activity that was suggested to be important for the acquisition of nucleotides. Similar results were obtained with the homolog from M. genitalium, MG186 (27,28). Similarly, the MPN284 homolog from Mycoplasma gallisepticum, MslA, was identified as an immunogenic virulence factor (29).…”

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confidence: 83%

Implication of Glycerol and Phospholipid Transporters in Mycoplasma pneumoniae Growth and Virulence

et al. 2013

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Mycoplasma pneumoniae, the causative agent of atypical pneumonia, is one of the bacteria with the smallest genomes that are nonetheless capable of independent life. Because of their longstanding close association with their human host, the bacteria have undergone reductive evolution and lost most biosynthetic abilities. Therefore, they depend on nutrients provided by the host that have to be taken up by the cell. Indeed, M. pneumoniae has a large set of hitherto unexplored transporters and lipoproteins that may be implicated in transport processes. Together, these proteins account for about 17% of the protein complement of M. pneumoniae. In the natural habitat of M. pneumoniae, human lung epithelial surfaces, phospholipids are the major available carbon source. Thus, the uptake and utilization of glycerol and glycerophosphodiesters that are generated by the activity of lipases are important for the nutrition of M. pneumoniae in its common habitat. In this study, we have investigated the roles of several potential transport proteins and lipoproteins in the utilization of glycerol and glycerophosphodiesters. On the basis of experiments with the corresponding mutant strains, our results demonstrate that the newly identified GlpU transport protein (MPN421) is responsible for the uptake of the glycerophosphodiester glycerophosphocholine, which is then intracellularly cleaved to glycerol-3-phosphate and choline. In addition, the proteins MPN076 and MPN077 are accessory factors in glycerophosphocholine uptake. Moreover, the lipoproteins MPN133 and MPN284 are essential for the uptake of glycerol. Our data suggest that they may act as binding proteins for glycerol and deliver glycerol molecules to the glycerol facilitator GlpF.

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confidence: 83%

Implication of Glycerol and Phospholipid Transporters in Mycoplasma pneumoniae Growth and Virulence

et al. 2013

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“…Nucleases have been reported as potential pathogenicity factors in other organisms as well [44]. Ureaplasmas belong to a group of organisms that import nucleotides for DNA and RNA synthesis.…”

Section: Resultsmentioning

confidence: 99%

Comparative genome analysis of 19 Ureaplasma urealyticum and Ureaplasma parvumstrains

Paralanov

Duffy

et al. 2012

BMC Microbiol

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BackgroundUreaplasma urealyticum (UUR) and Ureaplasma parvum (UPA) are sexually transmitted bacteria among humans implicated in a variety of disease states including but not limited to: nongonococcal urethritis, infertility, adverse pregnancy outcomes, chorioamnionitis, and bronchopulmonary dysplasia in neonates. There are 10 distinct serotypes of UUR and 4 of UPA. Efforts to determine whether difference in pathogenic potential exists at the ureaplasma serovar level have been hampered by limitations of antibody-based typing methods, multiple cross-reactions and poor discriminating capacity in clinical samples containing two or more serovars.ResultsWe determined the genome sequences of the American Type Culture Collection (ATCC) type strains of all UUR and UPA serovars as well as four clinical isolates of UUR for which we were not able to determine serovar designation. UPA serovars had 0.75−0.78 Mbp genomes and UUR serovars were 0.84−0.95 Mbp. The original classification of ureaplasma isolates into distinct serovars was largely based on differences in the major ureaplasma surface antigen called the multiple banded antigen (MBA) and reactions of human and animal sera to the organisms. Whole genome analysis of the 14 serovars and the 4 clinical isolates showed the mba gene was part of a large superfamily, which is a phase variable gene system, and that some serovars have identical sets of mba genes. Most of the differences among serovars are hypothetical genes, and in general the two species and 14 serovars are extremely similar at the genome level.ConclusionsComparative genome analysis suggests UUR is more capable of acquiring genes horizontally, which may contribute to its greater virulence for some conditions. The overwhelming evidence of extensive horizontal gene transfer among these organisms from our previous studies combined with our comparative analysis indicates that ureaplasmas exist as quasi-species rather than as stable serovars in their native environment. Therefore, differential pathogenicity and clinical outcome of a ureaplasmal infection is most likely not on the serovar level, but rather may be due to the presence or absence of potential pathogenicity factors in an individual ureaplasma clinical isolate and/or patient to patient differences in terms of autoimmunity and microbiome.

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“…Indeed, mycoplasmas evolutionary constraints in host adaptation forced to maintain membrane key components for extracellular degradation of nucleic acids, such as nucleases, and for transporting selected nucleotides precursors through the membrane, such as ATP-binding cassette (ABC) transport systems [1]. The importance of nucleases in mycoplasmas life cycle is reinforced by their detection in at least 20 Mycoplasma species [6], [7], [8], [9], [10], [11], [12], [13]. Several studies indicate that many of these enzymes are implicated in host pathogenicity and cytotoxicity.…”

Section: Introductionmentioning

confidence: 99%

Mycoplasma agalactiae MAG_5040 is a Mg2+-Dependent, Sugar-Nonspecific SNase Recognised by the Host Humoral Response during Natural Infection

Cacciotto

Addis²,

Coradduzza

et al. 2013

PLoS ONE

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In this study the enzymatic activity of Mycoplasma agalactiae MAG_5040, a magnesium-dependent nuclease homologue to the staphylococcal SNase was characterized and its antigenicity during natural infections was established. A UGA corrected version of MAG_5040, lacking the region encoding the signal peptide, was expressed in Escherichia coli as a GST fusion protein. Recombinant GST-MAG_5040 exhibits nuclease activity similar to typical sugar-nonspecific endo- and exonucleases, with DNA as the preferred substrate and optimal activity in the presence of 20 mM MgCl2 at temperatures ranging from 37 to 45°C. According to in silico analyses, the position of the gene encoding MAG_5040 is consistently located upstream an ABC transporter, in most sequenced mycoplasmas belonging to the Mycoplasma hominis group. In M. agalactiae, MAG_5040 is transcribed in a polycistronic RNA together with the ABC transporter components and with MAG_5030, which is predicted to be a sugar solute binding protein by 3D modeling and homology search. In a natural model of sheep and goats infection, anti-MAG_5040 antibodies were detected up to 9 months post infection. Taking into account its enzymatic activity, MAG_5040 could play a key role in Mycoplasma agalactiae survival into the host, contributing to host pathogenicity. The identification of MAG_5040 opens new perspectives for the development of suitable tools for the control of contagious agalactia in small ruminants.

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Mycoplasma pneumoniae Mpn133 is a cytotoxic nuclease with a glutamic acid-, lysine- and serine-rich region essential for binding and internalization but not enzymatic activity

Abstract: SummaryWe identified Mpn133 as a Ca

Cited by 42 publications

References 38 publications

Implication of Glycerol and Phospholipid Transporters in Mycoplasma pneumoniae Growth and Virulence

Implication of Glycerol and Phospholipid Transporters in Mycoplasma pneumoniae Growth and Virulence

Comparative genome analysis of 19 Ureaplasma urealyticum and Ureaplasma parvumstrains

Mycoplasma agalactiae MAG_5040 is a Mg2+-Dependent, Sugar-Nonspecific SNase Recognised by the Host Humoral Response during Natural Infection

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