An arginine/ornithine exchange system in Spiroplasma melliferum

Shirazi, Idit; Tarshis, Mark; Rottem, Shlomo

doi:10.1099/13500872-141-9-2323

Cited by 12 publications

(9 citation statements)

References 20 publications

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“…Spiroplasma melliferum and Sp. floricola were grown in a modified Saglio medium (Shirazi et al, 1995). The cultures were inoculated with a frozen inoculum at a level of 1-5 ' / o and then grown wuthout aeration for 24-48 h. The Mycoplasma and Acholeplasma species were grown at 37 "C whereas the Spiroplasma species were grown at 32 "C. Growth was monitored by measuring the OD,,, of the culture and by recording pH changes in the growth medium.…”

Section: Methodsmentioning

confidence: 99%

The thioredoxin reductase system of mycoplasmas

et al. 1997

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Representative species of the Mollicutes possess a thioredoxin reductase system (NTS) composed of a low-molecular-mass thioredoxin (TRX) and NADPH-binding thioredoxin reductase (NTR). The TRXs of Mycopkma pneumoniae and M. capricolum have molecular masses of 11-2 and 12 kDa, respectively, and are stable at 90 "C for 10 min. Both TRXs reacted with monospecif ic polyclonal anti bodies generated against the Bacillus subtilis TRX, but not with anti-Escherichia coli TRX antisera. The M. capricolum and M. pneumoniae NTRs were partially purified and were found to be active with the homologous TRX, but not with the TRX of B. subtilis or E. coli. The NTS activity had an optimal pH of 6-5-7-5 and was dependent on NADPH as an electron donor, a requirement which could not be fulfilled by NADH. The genes encoding the TRX and NTR (trxA and trxB) of M. pneumoniae were cloned and sequenced. The comparative analysis of the predicted amino acid sequence of trxA showed that the 11.2 kDa protein (102 aa) shared 26-68% sequence similarity with products of other known trxA genes and contained the conserved active site Cys-Gly-Pro-Cys. The predicted amino acid sequence of trxB contained 315 residues with a conserved NADPH binding domain and FAD binding domains I and II. The cysteine dithiol redox active region had isoleucine rather than threonine a t the active site, as compared with other NTRs. The high activity of the NTS in mycoplasmas suggests that mycoplasmas may have evolved the NTS to protect themselves from the consequences of their self-generated oxidative challenge.

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Section: Methodsmentioning

confidence: 99%

The thioredoxin reductase system of mycoplasmas

et al. 1997

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“…There are other arginine-and ornithine-related observations that may be relevant. Arginine/ornithine exchange systems have been described in various bacteria including Spiroplasma melliferum, lactic acid bacteria and P. aeruginosa (see Shirazi et al, 1995). Also, a staphylococcal siderophore, staphyloferrin A, has D-ornithine as a major structural component and addition of D-ornithine to iron-deficient medium stimulates siderophore production markedly (Konetschny-Rapp et al 1990).…”

Section: Arginine Uptake Studiesmentioning

confidence: 99%

Proline is biosynthesized from arginine in Staphylococcus aureus

et al. 1996

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Staphylococcus aureus NCTC 8325 exhibited a long lag phase (11 h) when inoculated into defined medium lacking proline, that could be shortened by increasing the concentration of arginine in the medium, or by supplying ornithine. Radioactivity from ~-['~C]arginine, but not ~-[l~C]glutamate was incorporated into a spot with the chromatographic mobility of [14C]proline in the pool metabolites fraction. Selection for transposon TnSI7-lacZ mutants impaired in arginine catabolism yielded four proline auxotrophs. Enzyme assays and precursor feeding experiments suggested that the major pathway for proline biosynthesis in S. aureus was from arginine via ornithine and A'-pyrroline 5-carboxylate, rather than from glutamate. Strain 8325 Pro+, a proline prototrophic variant obtained by cultivation of 8325 in the absence of proline, accumulated ~-[l~C]arginine from the medium at about eight times the rate of strain 8325, suggesting its response to proline starvation was to increase arginine uptake.1

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“…The uptake of 3 H-labeled low or nonexistent (30). The results clearly show that the rate of uptake of 3 H-labeled L-arginine by M. pneumoniae was much lower than that of M. fermentans (Fig.…”

Section: Resultsmentioning

confidence: 79%

“…Does the transporter function as uniporter, antiporter, or symporter? Among mollicutes, an arginine-ornithine exchange system has been reported only for spiroplasmas (30). Attempts have also failed to detect an arginine-ornithine exchange system for M. pneumoniae (A. Katzenell, unpublished data), although such a system has been identified in other bacteria, for example, Pseudomonas aeruginosa (38) and Streptococcus lactis (39).…”

Section: Discussionmentioning

confidence: 99%

Reconstitution of an Active Arginine Deiminase Pathway in Mycoplasma pneumoniae M129

Rechnitzer¹,

Rottem

Herrmann

2013

Infect Immun

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b Some species of the genus Mycoplasma code for the arginine deiminase pathway (ADI), which enables these bacteria to produce ATP from arginine by the successive reaction of three enzymes: arginine deiminase (ArcA), ornithine carbamoyltransferase (ArcB), and carbamate kinase (ArcC). It so far appears that independently isolated strains of Mycoplasma pneumoniae encode an almost identical truncated version of the ADI pathway in which the proteins ArcA and ArcB have lost their original enzymatic activities due to the deletion of significant regions of these proteins. To study the consequences of a functional ADI pathway, M. pneumoniae M129 was successfully transformed with the cloned functional arcA, arcB, and arcC genes from Mycoplasma fermentans. Enzymatic tests showed that while the M. pneumoniae ArcAB and ArcABC transformants possess functional arginine deiminase, ornithine carbamoyltransferase, and carbamate kinase, they were unable to grow on arginine as the sole energy source. Nevertheless, infection of a lung epithelial cell line, A549, with the M. pneumoniae transformants showed that almost 100% of the infected host cells were nonviable, while most of the lung cells infected with nontransformed M. pneumoniae were viable under the same experimental conditions. T he mycoplasmas (class Mollicutes) form a large group of prokaryotic microorganisms that are divided into nine genera with over 200 species. They are distinguished from ordinary bacteria by their small size and minute genome (0.58 to 2.20 Mb) and the total lack of a cell wall (1, 2). Phylogenetically, the mycoplasmas are related to Gram-positive bacteria, from which they developed by genome reduction (3).One criterion for classifying and characterizing mycoplasma species has been their energy source. For instance, glycolytic mycoplasmas generate energy from sugars by glycolysis, while some of the nonglycolytic mycoplasmas catabolize arginine by the arginine deiminase (ADI) pathway, consisting of three enzymes: arginine deiminase (ArcA), which hydrolyzes arginine to citrulline and ammonia; ornithine carbamoyltransferase (ArcB), which converts citrulline in the presence of phosphate to ornithine and carbamoylphosphate; and carbamate kinase (ArcC), which synthesizes ATP from carbamoylphosphate and ADP. For clarity and simplicity, throughout this article these protein and gene names are interchangeable.The presence of glycolytic and/or ADI pathways in bacteria has been analyzed in the past by selective growth conditions and enzymatic assays. Barile and coworkers (4) tested 18 Mycoplasma species, of which 10, including Mycoplasma hominis, M. arthriditis, and M. fermentans, could convert arginine to ATP by the arginine deiminase pathway. Among the ADI-negative Mycoplasma species was M. pneumoniae M129, whose complete genome has been sequenced and annotated (5). Surprisingly, an operon that contains coding DNA sequences (CDSs) with significant similarities to all three enzymes of the ADI pathway and a hypothetical arginine transporter have been described fo...

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An arginine/ornithine exchange system in Spiroplasma melliferum

Cited by 12 publications

References 20 publications

The thioredoxin reductase system of mycoplasmas

The thioredoxin reductase system of mycoplasmas

Proline is biosynthesized from arginine in Staphylococcus aureus

Reconstitution of an Active Arginine Deiminase Pathway in Mycoplasma pneumoniae M129

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