1
|
Knejzlík Z, Doležal M, Herkommerová K, Clarova K, Klíma M, Dedola M, Zborníková E, Rejman D, Pichová I. The mycobacterial guaB1 gene encodes a guanosine 5'-monophosphate reductase with a cystathionine-β-synthase domain. FEBS J 2022; 289:5571-5598. [PMID: 35338694 PMCID: PMC9790621 DOI: 10.1111/febs.16448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 02/11/2022] [Accepted: 03/24/2022] [Indexed: 12/30/2022]
Abstract
Mycobacteria express enzymes from both the de novo and purine-salvage pathways. However, the regulation of these processes and the roles of individual metabolic enzymes have not been sufficiently detailed. Both Mycobacterium tuberculosis (Mtb) and Mycobacterium smegmatis (Msm) possess three guaB genes, but information is only available on guaB2, which encodes an essential inosine 5'-monophosphate dehydrogenase (IMPDH) involved in de novo purine biosynthesis. This study shows that guaB1, annotated in databases as a putative IMPDH, encodes a guanosine 5'-monophosphate reductase (GMPR), which recycles guanosine monophosphate to inosine monophosphate within the purine-salvage pathway and contains a cystathionine-β-synthase domain (CBS), which is essential for enzyme activity. GMPR activity is allosterically regulated by the ATP/GTP ratio in a pH-dependent manner. Bioinformatic analysis has indicated the presence of GMPRs containing CBS domains across the entire Actinobacteria phylum.
Collapse
Affiliation(s)
- Zdeněk Knejzlík
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Michal Doležal
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Klára Herkommerová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Kamila Clarova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Martin Klíma
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Matteo Dedola
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Eva Zborníková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Dominik Rejman
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Iva Pichová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| |
Collapse
|
2
|
Breuer M, Earnest TM, Merryman C, Wise KS, Sun L, Lynott MR, Hutchison CA, Smith HO, Lapek JD, Gonzalez DJ, de Crécy-Lagard V, Haas D, Hanson AD, Labhsetwar P, Glass JI, Luthey-Schulten Z. Essential metabolism for a minimal cell. eLife 2019; 8:36842. [PMID: 30657448 PMCID: PMC6609329 DOI: 10.7554/elife.36842] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 01/17/2019] [Indexed: 11/29/2022] Open
Abstract
JCVI-syn3A, a robust minimal cell with a 543 kbp genome and 493 genes, provides a versatile platform to study the basics of life. Using the vast amount of experimental information available on its precursor, Mycoplasma mycoides capri, we assembled a near-complete metabolic network with 98% of enzymatic reactions supported by annotation or experiment. The model agrees well with genome-scale in vivo transposon mutagenesis experiments, showing a Matthews correlation coefficient of 0.59. The genes in the reconstruction have a high in vivo essentiality or quasi-essentiality of 92% (68% essential), compared to 79% in silico essentiality. This coherent model of the minimal metabolism in JCVI-syn3A at the same time also points toward specific open questions regarding the minimal genome of JCVI-syn3A, which still contains many genes of generic or completely unclear function. In particular, the model, its comparison to in vivo essentiality and proteomics data yield specific hypotheses on gene functions and metabolic capabilities; and provide suggestions for several further gene removals. In this way, the model and its accompanying data guide future investigations of the minimal cell. Finally, the identification of 30 essential genes with unclear function will motivate the search for new biological mechanisms beyond metabolism. One way that researchers can test whether they understand a biological system is to see if they can accurately recreate it as a computer model. The more they learn about living things, the more the researchers can improve their models and the closer the models become to simulating the original. In this approach, it is best to start by trying to model a simple system. Biologists have previously succeeded in creating ‘minimal bacterial cells’. These synthetic cells contain fewer genes than almost all other living things and they are believed to be among the simplest possible forms of life that can grow on their own. The minimal cells can produce all the chemicals that they need to survive – in other words, they have a metabolism. Accurately recreating one of these cells in a computer is a key first step towards simulating a complete living system. Breuer et al. have developed a computer model to simulate the network of the biochemical reactions going on inside a minimal cell with just 493 genes. By altering the parameters of their model and comparing the results to experimental data, Breuer et al. explored the accuracy of their model. Overall, the model reproduces experimental results, but it is not yet perfect. The differences between the model and the experiments suggest new questions and tests that could advance our understanding of biology. In particular, Breuer et al. identified 30 genes that are essential for life in these cells but that currently have no known purpose. Continuing to develop and expand models like these to reproduce more complex living systems provides a tool to test current knowledge of biology. These models may become so advanced that they could predict how living things will respond to changing situations. This would allow scientists to test ideas sooner and make much faster progress in understanding life on Earth. Ultimately, these models could one day help to accelerate medical and industrial processes to save lives and enhance productivity.
Collapse
Affiliation(s)
- Marian Breuer
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Tyler M Earnest
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, United States
| | | | - Kim S Wise
- J Craig Venter Institute, La Jolla, United States
| | - Lijie Sun
- J Craig Venter Institute, La Jolla, United States
| | | | | | | | - John D Lapek
- Department of Pharmacology and School of Pharmacy, University of California at San Diego, La Jolla, United States
| | - David J Gonzalez
- Department of Pharmacology and School of Pharmacy, University of California at San Diego, La Jolla, United States
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University of Florida, Gainesville, United States
| | - Drago Haas
- Department of Microbiology and Cell Science, University of Florida, Gainesville, United States
| | - Andrew D Hanson
- Horticultural Sciences Department, University of Florida, Gainesville, United States
| | - Piyush Labhsetwar
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, United States
| | - John I Glass
- J Craig Venter Institute, La Jolla, United States
| | - Zaida Luthey-Schulten
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, United States
| |
Collapse
|
3
|
Yu T, Wang Y, Zhang H, Johnson CH, Jiang Y, Li X, Wu Z, Liu T, Krausz KW, Yu A, Gonzalez FJ, Huang M, Bi H. Metabolomics reveals mycoplasma contamination interferes with the metabolism of PANC-1 cells. Anal Bioanal Chem 2016; 408:4267-73. [PMID: 27074779 DOI: 10.1007/s00216-016-9525-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/18/2016] [Accepted: 03/24/2016] [Indexed: 10/22/2022]
Abstract
Mycoplasma contamination is a common problem in cell culture and can alter cellular functions. Since cell metabolism is either directly or indirectly involved in every aspect of cell function, it is important to detect changes to the cellular metabolome after mycoplasma infection. In this study, liquid chromatography mass spectrometry (LC/MS)-based metabolomics was used to investigate the effect of mycoplasma contamination on the cellular metabolism of human pancreatic carcinoma cells (PANC-1). Multivariate analysis demonstrated that mycoplasma contamination induced significant metabolic changes in PANC-1 cells. Twenty-three metabolites were identified and found to be involved in arginine and purine metabolism and energy supply. This study demonstrates that mycoplasma contamination significantly alters cellular metabolite levels, confirming the compelling need for routine checking of cell cultures for mycoplasma contamination, particularly when used for metabolomics studies. Graphical abstract Metabolomics reveals mycoplasma contamination changes the metabolome of PANC-1 cells.
Collapse
Affiliation(s)
- Tao Yu
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132# Waihuandong Rd, University City of Guangzhou, Guangzhou, 510006, China
| | - Yongtao Wang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132# Waihuandong Rd, University City of Guangzhou, Guangzhou, 510006, China
| | - Huizhen Zhang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132# Waihuandong Rd, University City of Guangzhou, Guangzhou, 510006, China
| | - Caroline H Johnson
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, 60 College Street, New Haven, CT, 06520, USA
| | - Yiming Jiang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132# Waihuandong Rd, University City of Guangzhou, Guangzhou, 510006, China
| | - Xiangjun Li
- Thermo Fisher Scientific, Xin Jinqiao Rd., Shanghai, 201206, China
| | - Zeming Wu
- Thermo Fisher Scientific, Xin Jinqiao Rd., Shanghai, 201206, China
| | - Tian Liu
- Thermo Fisher Scientific, Xin Jinqiao Rd., Shanghai, 201206, China
| | - Kristopher W Krausz
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Aiming Yu
- Department of Biochemistry and Molecular Medicine, UC Davis Medical Center, Sacramento, CA, 95817, USA
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Min Huang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132# Waihuandong Rd, University City of Guangzhou, Guangzhou, 510006, China
| | - Huichang Bi
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132# Waihuandong Rd, University City of Guangzhou, Guangzhou, 510006, China.
| |
Collapse
|
4
|
Sun R, Wang L. Inhibition of Mycoplasma pneumoniae growth by FDA-approved anticancer and antiviral nucleoside and nucleobase analogs. BMC Microbiol 2013; 13:184. [PMID: 23919755 PMCID: PMC3750255 DOI: 10.1186/1471-2180-13-184] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/24/2013] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Mycoplasma pneumoniae (Mpn) is a human pathogen that causes acute and chronic respiratory diseases and has been linked to many extrapulmonary diseases. Due to the lack of cell wall, Mpn is resistant to antibiotics targeting cell wall synthesis such as penicillin. During the last 10 years macrolide-resistant Mpn strains have been frequently reported in Asian countries and have been spreading to Europe and the United States. Therefore, new antibiotics are needed. In this study, 30 FDA-approved anticancer or antiviral drugs were screened for inhibitory effects on Mpn growth and selected analogs were further characterized by inhibition of target enzymes and metabolism of radiolabeled substrates. RESULTS Sixteen drugs showed varying inhibitory effects and seven showed strong inhibition of Mpn growth. The anticancer drug 6-thioguanine had a MIC (minimum inhibitory concentration required to cause 90% of growth inhibition) value of 0.20 μg ml(-1), whereas trifluorothymidine, gemcitabine and dipyridamole had MIC values of approximately 2 μg ml(-1). In wild type Mpn culture the presence of 6-thioguanine and dipyridamole strongly inhibited the uptake and metabolism of hypoxanthine and guanine while gemcitabine inhibited the uptake and metabolism of all nucleobases and thymidine. Trifluorothymidine and 5-fluorodeoxyuridine, however, stimulated the uptake and incorporation of radiolabeled thymidine and this stimulation was due to induction of thymidine kinase activity. Furthermore, Mpn hypoxanthine guanine phosphoribosyl transferase (HPRT) was cloned, expressed, and characterized. The 6-thioguanine, but not other purine analogs, strongly inhibited HPRT, which may in part explain the observed growth inhibition. Trifluorothymidine and 5-fluorodeoxyuridine were shown to be good substrates and inhibitors for thymidine kinase from human and Mycoplasma sources. CONCLUSION We have shown that several anticancer and antiviral nucleoside and nucleobase analogs are potent inhibitors of Mpn growth and that the mechanism of inhibition are most likely due to inhibition of enzymes in the nucleotide biosynthesis pathway and nucleoside transporter. Our results suggest that enzymes in Mycoplasma nucleotide biosynthesis are potential targets for future design of antibiotics against Mycoplasma infection.
Collapse
Affiliation(s)
- Ren Sun
- Department of Anatomy, Physiology, and Biochemistry, Swedish University of Agricultural Sciences, The Biomedical Centre, Box 575, SE-751 23 Uppsala, Sweden
| | - Liya Wang
- Department of Anatomy, Physiology, and Biochemistry, Swedish University of Agricultural Sciences, The Biomedical Centre, Box 575, SE-751 23 Uppsala, Sweden
| |
Collapse
|
5
|
Liekens S, Bronckaers A, Balzarini J. Improvement of purine and pyrimidine antimetabolite-based anticancer treatment by selective suppression of mycoplasma-encoded catabolic enzymes. Lancet Oncol 2009; 10:628-35. [PMID: 19482252 DOI: 10.1016/s1470-2045(09)70037-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Most mycoplasmas are present as commensals, colonising the mucosa of our respiratory and gastrointestinal tract. Experimental data suggest that the long-term association of certain mycoplasma species with mammalian cells might favour host-cell transformation and malignancy. Moreover, increased mycoplasma infection has been noted in several cancers. Despite efforts to develop target-specific anticancer drugs, current cancer treatment still relies on the use of nucleobase or nucleoside-based analogues. Here, we provide experimental evidence that nucleoside-metabolising catabolic enzymes expressed by mycoplasmas substantially compromise the efficacy of nucleoside antimetabolites used in the treatment of cancer. We also suggest potential methods for improving future chemotherapy by suppressing mycoplasma-mediated catabolism of the anticancer nucleoside analogues.
Collapse
Affiliation(s)
- Sandra Liekens
- Rega Institute for Medical Research, K U Leuven, Leuven, Belgium
| | | | | |
Collapse
|
6
|
Schmidt JA, Browning GF, Markham PF. Mycoplasma hyopneumoniae mhp379 is a Ca2+-dependent, sugar-nonspecific exonuclease exposed on the cell surface. J Bacteriol 2007; 189:3414-24. [PMID: 17307846 PMCID: PMC1855908 DOI: 10.1128/jb.01835-06] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Accepted: 02/09/2007] [Indexed: 12/30/2022] Open
Abstract
Mycoplasma hyopneumoniae mhp379 is a putative lipoprotein that shares significant amino acid sequence similarity with a family of bacterial thermostable nucleases. To examine the nuclease activity of mhp379, the gene was cloned and expressed in Escherichia coli following the deletion of the amino-terminal signal sequence and prokaryotic lipoprotein cleavage site and mutagenesis of the mycoplasma TGA tryptophan codons to TGG. The recombinant fusion protein yielded a 33-kDa thrombin cleavage product, corresponding in size to the mature mhp379 protein. Exonuclease activity was indicated by agarose gel electrophoresis analysis of the reaction products that were released when different nucleic acid substrates were used. Endonuclease activity was also indicated by the digestion of closed circular plasmid DNA. The recombinant mhp379 fusion protein completely digested single-stranded DNA, double-stranded DNA (dsDNA), and RNA. The optimal reaction conditions were determined with a novel nuclease assay based on the enhancement of fluorescence of SYBR green I bound to dsDNA. Optimal activity was observed in the presence of calcium ions at a concentration of 15 mM and a pH of 9.5. No nuclease activity was observed in the absence of calcium ions. Mycoplasmas do not have the ability to synthesize nucleic acid precursors, and thus, nucleases are likely to be important in the acquisition of precursors for the synthesis of nucleic acids. Homologs of an ATP-binding cassette (ABC) transport system were identified immediately downstream of the gene encoding mhp379, and two homologs of M. pneumoniae lipoprotein multigene family 2 were also identified immediately upstream. Homologs of mhp379 were identified in the sequenced genomes of a number of mycoplasma species, and in most cases the homologous ABC transport system was identified immediately downstream of the homologous gene; in several cases a homolog of M. pneumoniae lipoprotein multigene family 2 was also identified immediately upstream. These observations suggest that mhp379 comprises part of a conserved ABC transport operon in mycoplasmas and that the exonuclease activity of mhp379 may be associated with the conserved function of the ABC transport system in the import of nucleic acid precursors. This is the first study to identify the gene and characterize the activity of a mycoplasma exonuclease.
Collapse
Affiliation(s)
- Jonathan A Schmidt
- Veterinary Preclinical Centre, Department of Veterinary Science, The University of Melbourne, Parkville, Victoria 3010, Australia
| | | | | |
Collapse
|
7
|
|
8
|
Wang L, Westberg J, Bölske G, Eriksson S. Novel deoxynucleoside-phosphorylating enzymes in mycoplasmas: evidence for efficient utilization of deoxynucleosides. Mol Microbiol 2001; 42:1065-73. [PMID: 11737647 DOI: 10.1046/j.1365-2958.2001.02700.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mycoplasmas are unable to synthesize purine and pyrimidine bases de novo. Therefore, salvage of existing nucleosides and bases is essential for their survival. Four mycoplasma species were studied with regard to their ability to phosphorylate deoxynucleosides. High levels of thymidine kinase (TK), deoxycytidine kinase (dCK), deoxyguanosine kinase (dGK) and deoxyadenosine kinase (dAK) activities were detected in extracts from Mycoplasma pneumoniae, Mycoplasma mycoides subsp. mycoides SC (M. mymySC), Acholeplasma laidlawii (A. laidlawii) and Mycoplasma arginini (M. arginini). Nucleoside phosphotransferase activities were found at high levels in A. laidlawii and low levels in M. arginini. Pyrophosphate-dependent deoxynucleoside kinase activities were detected mainly in A. laidlawii and M. mymySC extracts. Two open reading frames were identified in the M. mymySC genome; one showed 25% sequence identity to human dGK and the other one had about 26% sequence identity to human TK1. The M. mymySC dGK-like enzyme was cloned, expressed in Escherichia coli and affinity-purified. This enzyme phosphorylated dAdo, dGuo and dCyd, and the highest catalytic rate was with dAdo as substrate. Therefore, we suggest that this enzyme should be named deoxyadenosine kinase. The physiological role of mycoplasma dAK and TK may be to support the unusually large dATP and dTTP pools required for replication of mycoplasma genomes.
Collapse
Affiliation(s)
- L Wang
- Department of Veterinary Medical Chemistry, The Swedish University of Agricultural Sciences, The Biomedical Centre, SE-751 23 Uppsala, Sweden.
| | | | | | | |
Collapse
|
9
|
Pollack JD, Williams MV, McElhaney RN. The comparative metabolism of the mollicutes (Mycoplasmas): the utility for taxonomic classification and the relationship of putative gene annotation and phylogeny to enzymatic function in the smallest free-living cells. Crit Rev Microbiol 1998; 23:269-354. [PMID: 9439886 DOI: 10.3109/10408419709115140] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mollicutes or mycoplasmas are a class of wall-less bacteria descended from low G + C% Gram-positive bacteria. Some are exceedingly small, about 0.2 micron in diameter, and are examples of the smallest free-living cells known. Their genomes are equally small; the smallest in Mycoplasma genitalium is sequenced and is 0.58 mb with 475 ORFs, compared with 4.639 mb and 4288 ORFs for Escherichia coli. Because of their size and apparently limited metabolic potential, Mollicutes are models for describing the minimal metabolism necessary to sustain independent life. Mollicutes have no cytochromes or the TCA cycle except for malate dehydrogenase activity. Some uniquely require cholesterol for growth, some require urea and some are anaerobic. They fix CO2 in anaplerotic or replenishing reactions. Some require pyrophosphate not ATP as an energy source for reactions, including the rate-limiting step of glycolysis: 6-phosphofructokinase. They scavenge for nucleic acid precursors and apparently do not synthesize pyrimidines or purines de novo. Some genera uniquely lack dUTPase activity and some species also lack uracil-DNA glycosylase. The absence of the latter two reactions that limit the incorporation of uracil or remove it from DNA may be related to the marked mutability of the Mollicutes and their tachytelic or rapid evolution. Approximately 150 cytoplasmic activities have been identified in these organisms, 225 to 250 are presumed to be present. About 100 of the core reactions are graphically linked in a metabolic map, including glycolysis, pentose phosphate pathway, arginine dihydrolase pathway, transamination, and purine, pyrimidine, and lipid metabolism. Reaction sequences or loci of particular importance are also described: phosphofructokinases, NADH oxidase, thioredoxin complex, deoxyribose-5-phosphate aldolase, and lactate, malate, and glutamate dehydrogenases. Enzymatic activities of the Mollicutes are grouped according to metabolic similarities that are taxonomically discriminating. The arrangements attempt to follow phylogenetic relationships. The relationships of putative gene assignments and enzymatic function in My. genitalium, My. pneumoniae, and My. capricolum subsp. capricolum are specially analyzed. The data are arranged in four tables. One associates gene annotations with congruent reports of the enzymatic activity in these same Mollicutes, and hence confirms the annotations. Another associates putative annotations with reports of the enzyme activity but from different Mollicutes. A third identifies the discrepancies represented by those enzymatic activities found in Mollicutes with sequenced genomes but without any similarly annotated ORF. This suggests that the gene sequence is significantly different from those already deposited in the databanks and putatively annotated with the same function. Another comparison lists those enzymatic activities that are both undetected in Mollicutes and not associated with any ORF. Evidence is presented supporting the theory that there are relatively small gene sequences that code for functional centers of multiple enzymatic activity. This property is seemingly advantageous for an organism with a small genome and perhaps under some coding restraint. The data suggest that a concept of "remnant" or "useless genes" or "useless enzymes" should be considered when examining the relationship of gene annotation and enzymatic function. It also suggests that genes in addition to representing what cells are doing or what they may do, may also identify what they once might have done and may never do again.
Collapse
Affiliation(s)
- J D Pollack
- Department of Medical Microbiology and Immunology, Ohio State University, Columbus 43210, USA.
| | | | | |
Collapse
|
10
|
Youil R, Finch LR. Isolation and characterization of Mycoplasma mycoides subsp. mycoides mutants deficient in nucleoside monophosphate transport. J Bacteriol 1988; 170:5922-4. [PMID: 3056924 PMCID: PMC211704 DOI: 10.1128/jb.170.12.5922-5924.1988] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
To select mutants lacking dAMP uptake, log-phase cells of Mycoplasma mycoides subsp. mycoides Y were incubated with high-specific-activity [32P]dAMP and then stored several weeks at -20 degrees C to allow 32P decay before plating out. Mutants were screened for lack of labeling by [32P]dAMP. Two mutants were studied further by uptake and growth experiments with other nucleotides.
Collapse
Affiliation(s)
- R Youil
- Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Victoria, Australia
| | | |
Collapse
|
11
|
Pyle LE, Corcoran LN, Cocks BG, Bergemann AD, Whitley JC, Finch LR. Pulsed-field electrophoresis indicates larger-than-expected sizes for mycoplasma genomes. Nucleic Acids Res 1988; 16:6015-25. [PMID: 2840639 PMCID: PMC336844 DOI: 10.1093/nar/16.13.6015] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The sizes of large DNA fragments produced from genomes of members of the Mycoplasmataceae by digestion with restriction endonucleases having infrequent (1 to 3) cleavage sites within the genome were estimated from their mobility in contour-clamped homogeneous electric field (CHEF) agarose gel electrophoresis by comparison with yeast chromosomal DNA markers. The estimates of total genome size for 7 strains of 6 species ranged from approximately 900 kilo base pairs (kb) for Ureaplasma urealyticum 960T to 1330 kb for M. mycoides subsp. mycoides, GC-1176. The values derived from this new method are considerably higher than those of approximately 500 Mdaltons or 750 kb previously reported for genome sizes in members of the Mycoplasmataceae.
Collapse
Affiliation(s)
- L E Pyle
- Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Victoria, Australia
| | | | | | | | | | | |
Collapse
|
12
|
Pyle LE, Finch LR. Preparation and FIGE separation of infrequent restriction fragments from Mycoplasma mycoides DNA. Nucleic Acids Res 1988; 16:2263-8. [PMID: 2833729 PMCID: PMC338214 DOI: 10.1093/nar/16.5.2263] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Use of procedures for obtaining satisfactory preparation and digestion of intact DNA of Mycoplasma mycoides subsp. mycoides Y in agarose blocks is reported. The use of inverted field agarose gel electrophoresis (FIGE) for separation of the small number of fragments derived from the genome by several restriction endonuclease digestions is shown. An effect that fragments containing replication forks remain in the well during FIGE, distorting the representative yield of restriction fragments on the gels, is overcome by incubating cells with chloramphenicol for 1 1/2 h before harvest to allow rounds of replication to go to completion without new initiations of DNA synthesis.
Collapse
Affiliation(s)
- L E Pyle
- Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Victoria, Australia
| | | |
Collapse
|
13
|
Abstract
A 1.7-kb plasmid was isolated from a large colony type strain of Mycoplasma mycoides subsp. mycoides. It was cloned into the Escherichia coli vector M13mp19, and DNA from the resultant recombinant was used to construct a restriction map of the plasmid. Because mycoplasmas show deviation from normal coding patterns, the availability of a mycoplasma plasmid could be useful in the development of a cloning vector for them.
Collapse
Affiliation(s)
- A D Bergemann
- Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Victoria, Australia
| | | |
Collapse
|
14
|
McElwain MC, Pollack JD. Synthesis of deoxyribomononucleotides in Mollicutes: dependence on deoxyribose-1-phosphate and PPi. J Bacteriol 1987; 169:3647-53. [PMID: 3038846 PMCID: PMC212445 DOI: 10.1128/jb.169.8.3647-3653.1987] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Cell extracts of Acholeplasma laidlawii B-PG9, Acholeplasma morum S2, Mycoplasma capricolum 14, and Mycoplasma gallisepticum S6 were examined for 37 cytoplasmic enzyme activities involved in the salvage and biosynthesis of purines. All of these organisms had adenine phosphoribosyltransferase activity (EC 2.4.2.7) and hypoxanthine phosphoribosyltransferase activity (EC 2.4.2.8). All of these organisms had purine-nucleoside phosphorylase activity (EC 2.4.2.1) in the synthetic direction using ribose-1-phosphate (R-1-P) or deoxyribose-1-phosphate (dR-1-P); this activity generated ribonucleosides or deoxyribonucleosides, respectively. The pyrimidine nucleobase uracil could also be ribosylated by using either R-1-P or dR-1-P as a donor. The synthesis of deoxyribonucleosides from nucleobases and dR-1-P has been reported from only one other procaryote, Escherichia coli (L. A. Mason and J. O. Lampen, J. Biol. Chem. 193:539-547, 1951). The reverse of this phosphorylase reaction is more widely known, and we found such activity in all mollicutes studied. Some Acholeplasma species but not the Mycoplasma species can phosphorylate deoxyribonucleosides to deoxyribomononucleotides by a PPi-dependent deoxyribonucleoside kinase activity, which was first reported in this group for the ribose analogs (V. V. Tryon and J. D. Pollack, Int. J. Syst. Bacteriol. 35:497-501, 1985). This is the first report of PPi-dependent purine deoxyribonucleoside kinase activity. An ATP-dependent purine deoxyribonucleoside kinase activity is known only in salmon milt extracts (H. L. A. Tarr, Can. J. Biochem. 42:1535-1545, 1964). Deoxyribomononucleotidase activity was also found in cytoplasmic extracts of these mollicutes. This is the first report of deoxyribomononucleotidase activity.
Collapse
|
15
|
Williams MV, Pollack JD. Pyrimidine deoxyribonucleotide metabolism in Acholeplasma laidlawii B-PG9. J Bacteriol 1985; 161:1029-33. [PMID: 3972768 PMCID: PMC215002 DOI: 10.1128/jb.161.3.1029-1033.1985] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Extracts of Acholeplasma laidlawii B-PG9 were examined for the enzymes associated with the interconversion of the pyrimidine deoxyribonucleotides and the biosynthesis of thymidine nucleotides. A. laidlawii B-PG9 possessed deaminases for deoxycytidine and dCMP, pyrophosphatases for dUTP, phosphorylases for thymidine and uridine, and a membrane-associated pyrimidine deoxyribonucleoside monophosphate phosphatase activity. The role these enzyme activities have in the generation of deoxyribose-1-phosphate during growth may explain the ability of A. laidlawii B-PG9 to utilize either thymine or thymidine for biosynthesis.
Collapse
|
16
|
Tryon VV, Pollack D. Purine metabolism in Acholeplasma laidlawii B: novel PPi-dependent nucleoside kinase activity. J Bacteriol 1984; 159:265-70. [PMID: 6330034 PMCID: PMC215623 DOI: 10.1128/jb.159.1.265-270.1984] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Acholeplasma laidlawii B-PG9 was examined for 16 cytoplasmic enzymes with activity for purine salvage and interconversion. Phosphoribosyltransferase activities for adenine, guanine, xanthine, and hypoxanthine were shown. Adenine, guanine, xanthine, and hypoxanthine were ribosylated to their nucleoside. Adenosine, inosine, xanthosine, and guanosine were converted to their base. No ATP-dependent phosphorylation of nucleosides to mononucleotides was found. However, PPi-dependent phosphorylation of adenosine, inosine, and guanosine to AMP, inosine monophosphate, and GMP, respectively, was detected. Nucleotidase activity for AMP, inosine monophosphate, xanthosine monophosphate, and GMP was also found. Interconversion of GMP to AMP was detected. Enzyme activities for the interconversion of AMP to GMP were not detected. Therefore, A. laidlawii B-PG9 cannot synthesize guanylates from adenylates or inosinates. De novo synthesis of purines was not detected. This study demonstrates that A. laidlawii B-PG9 has the enzyme activities for the salvage and limited interconversion of purines and, except for purine nucleoside kinase activity, is similar to Mycoplasma mycoides subsp. mycoides. This is the first report of a PPi-dependent nucleoside kinase activity in any organism.
Collapse
|
17
|
Neale GA, Mitchell A, Finch LR. Uptake and utilization of deoxynucleoside 5'-monophosphates by Mycoplasma mycoides subsp. mycoides. J Bacteriol 1984; 158:943-7. [PMID: 6373743 PMCID: PMC215532 DOI: 10.1128/jb.158.3.943-947.1984] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Mycoplasma mycoides subsp. mycoides has been shown to possess an unusual capacity for the uptake and utilization of exogenous deoxyribonucleoside 5'-monophosphates intact without prior dephosphorylation. In this study, it was found that once inside the cell, deoxyribonucleoside 5'-monophosphates were rapidly phosphorylated to the triphosphate level and incorporated into DNA. Catabolism of deoxyribonucleoside 5'-monophosphates was also observed. Competition studies indicated that a single uptake system with a higher affinity for deoxyribonucleotides mediates the uptake of nucleoside 5'-monophosphates.
Collapse
|
18
|
Neale GA, Mitchell A, Finch LR. Enzymes of pyrimidine deoxyribonucleotide metabolism in Mycoplasma mycoides subsp. mycoides. J Bacteriol 1983; 156:1001-5. [PMID: 6139361 PMCID: PMC217942 DOI: 10.1128/jb.156.3.1001-1005.1983] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Cell-free extracts of Mycoplasma mycoides subsp. mycoides were assayed for enzymes associated with the salvage synthesis of pyrimidine deoxyribonucleotides. They possessed kinases for deoxycytidine, (d)CMP, thymidine (deoxyuridine), dTMP, and nucleoside diphosphates; dCTPase and dUTPase; dCMP deaminase; thymidine (deoxyuridine) phosphorylase; and dUMP (dTMP) phosphatase. The existence of these enzymic activities together with ribonucleoside diphosphate reductase explains the capacity of cytidine to provide M. mycoides with deoxyribose for the synthesis of thymidine nucleotides from thymine.
Collapse
|
19
|
Salih MM, Ernø H, Simonsen V. Electrophoretic analysis of isoenzymes of mycoplasma species. Acta Vet Scand 1983. [PMID: 6869144 DOI: 10.1186/bf03546754] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
20
|
Neale GA, Mitchell A, Finch LR. Pathways of pyrimidine deoxyribonucleotide biosynthesis in Mycoplasma mycoides subsp. mycoides. J Bacteriol 1983; 154:17-22. [PMID: 6339469 PMCID: PMC217425 DOI: 10.1128/jb.154.1.17-22.1983] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
By measuring the specific activity of deoxyribonucleotides isolated from DNA after the incorporation of 14C-labeled precursors with and without competition from other nucleotide precursors, we defined the major pathways of pyrimidine deoxyribonucleotide synthesis in Mycoplasma mycoides subsp. mycoides. Uracil, guanine, and thymine are required for the synthesis of nucleotides. Cytidine competed effectively with uracil to provide all of the deoxycytidine nucleotide, as well as most of the deoxyribose-1-phosphate, for the synthesis of thymidylate from thymine via thymidine phosphorylase. Each of dUMP, dCMP, and dTMP competed with cytidine for incorporation into DNA thymidylate. Appreciable incorporation of exogenous deoxyribonucleoside 5'-monophosphates into DNA without prior dephosphorylation was observed. Dephosphorylation also occurred since the added deoxyribonucleotide provided phosphate for the synthesis of the other nucleotides in DNA in competition with the 32Pi in the growth medium. Hydroxyurea inhibited cell growth and decreased the intracellular level of dATP, consistent with the action of a ribonucleoside diphosphate reductase with regulatory properties similar to those of the Escherichia coli enzyme.
Collapse
|
21
|
Salih MM, Ernø H, Simonsen V. Electrophoretic analysis of isoenzymes of mycoplasma species. Acta Vet Scand 1983; 24:14-33. [PMID: 6869144 PMCID: PMC8291283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The purpose of this paper is to further characterize and determine relatedness among some Mycoplasma species or serogroups of significant practical veterinary interest. Twenty-four strains were examined for the presence of 35 enzymes by horizontal starch gel electrophoresis, revealing a total of 127 different electromorphs of 30 enzymes. Inter- as well as intraspecific differences were found demonstrating the application of isoenzyme studies in classification as well as epidemiology. It is concluded that the F38 group of MacOwan and group 7 of Leach constitute 2 new species, The elevation of the 2 subspecies of M. mycoides (mycoides and capri) to species level is favoured, but it is suggested that a decision be taken internationally, considering the practical consequences of a given nomenclature. Three alternative possibilities for classification are presented. Regarding identification the results suggest that the presence or absence of maltase and ornithine transcarbamylase indicate whether an isolate is related to the agent of contagious bovine pleuropneumonia or merely a representative of either the caprine LG type of M. mycoides subsp. mycoides or the classical caprine subspecies, M. mycoides subsp. capri.
Collapse
|
22
|
Pollack JD, Tryon VV, Beaman KD. The metabolic pathways of Acholeplasma and Mycoplasma: an overview. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 1983; 56:709-16. [PMID: 6206660 PMCID: PMC2590559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The metabolism of the Mollicutes Acholeplasma and Mycoplasma may be characterized as restricted, for example, by virtue of the apparent absence of cytochrome pigments. Some Mollicutes have lowered ECA values during their logarithmic growth phase, which we speculate may be related to insufficient substrate phosphorylation or insufficient ATP synthesis linked to glycolysis. We found that PEP is carboxylated by preparations of A. laidlawii, but not by other Mollicutes; thus in this organism oxaloacetate from PEP may be a link to other pathways. We found phosphoribosylpyrophosphate in A. laidlawii, which suggests that ribosylation of purines and pyrimidines occurs in Mollicutes other than M. mycoides.
Collapse
|
23
|
O'Brien SJ, Simonson JM, Grabowski MW, Barile MF. Analysis of multiple isoenzyme expression among twenty-two species of Mycoplasma and Acholeplasma. J Bacteriol 1981; 146:222-32. [PMID: 7217001 PMCID: PMC217073 DOI: 10.1128/jb.146.1.222-232.1981] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Crude extracts of triple-cloned, purified cultures of 22 species of Mycoplasma and Acholeplasma were examined for expression of 21 isozyme systems routinely used to type mammalian cells. Nine previously described enzymes (purine nucleoside phosphorylase, adenylate kinase, dipeptidase, esterase, glyceraldehyde-3-phosphate dehydrogenase, glucose phosphate isomerase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and superoxide dismutase) and three enzymes not previously reported in mycoplasma (triose phosphate isomerase, inorganic pyrophosphatase, and acid phosphatase) were detected in some or all of the species examined. These findings provide new information on the enzymatic expressions of these organisms. Three of the isozyme systems (superoxide dismutase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase) were present in Acholeplasma species but not in any Mycoplasma species. The characteristic pattern of electrophoretic mobility of the 12 isozyme systems also provides a useful biochemical property for identification, characterization, and classification of these mycoplasmas. Mycoplasma isozyme expression for seven of the enzymes were readily detected in various infected-cell culture lines by using either cell extracts or concentrated cell culture fluids. Mycoplasma-specific enzymes found in infected-cell extracts had the same electrophoretic mobility patterns as enzymes obtained from broth-grown mycoplasmas of the same species. Expression of homologous mammalian enzymes was not detectably altered by infection with mycoplasmas.
Collapse
|
24
|
Abstract
The major pathways of ribonucleotide biosynthesis in Mycoplasma mycoides subsp. mycoides have been proposed from studies on its use of radioactive purines and pyrimidines. To interpret more fully the observed pattern of pyrimidine usage, cell extracts of this organism have been assayed for several enzymes associated with the salvage synthesis of pyrimidine nucleotides. M. mycoides possessed uracil phosphoribosyltransferase, uridine phosphorylase, uridine (cytidine) kinase, uridine 5'-monophosphate kinase, and cytidine 5'-triphosphate synthetase. No activity for phosphorolysis of cytidine was detected, and no in vitro conditions were found to give measurable deamination of cytidine. Of the two potential pathways for incorporation of uridine, our data suggest that this precursor would largely undergo initial phosphorolysis to uracil and ribose-1-phosphate. Conversely, cytidine is phosphorylated directly to cytidine 5'-monophosphate in its major utilization, although conversion of cytidine to uracil, uridine, and uridine nucleotide has been observed in vivo, at least when uracil is provided in the growth medium. Measurements of intracellular nucleotide contents and their changes on additions of pyrimidine precursors have allowed suggestions as to the operation of regulatory mechanisms on pyrimidine nucleotide biosynthesis in M. mycoides in vivo. With uracil alone or uracil plus uridine as precursors of pyrimidine ribonucleotides, the regulation of uracil phosphoribosyltransferase and cytidine 5'-triphosphate synthetase is probably most important in determining the rate of pyrimidine nucleotide synthesis. When cytidine supplements uracil in the growth medium, control of cytidine kinase activity would also be important in this regard.
Collapse
|