title: DNA repair in Mycoplasma gallisepticum.
abstract: BACKGROUND
  DNA repair is essential for the maintenance of genome stability in all living beings. Genome size as well as the repertoire and abundance of DNA repair components may vary among prokaryotic species. The bacteria of the Mollicutes class feature a small genome size, absence of a cell wall, and a parasitic lifestyle. A small number of genes make Mollicutes a good model for a "minimal cell" concept.
  
  
  RESULTS
  In this work we studied the DNA repair system of Mycoplasma gallisepticum on genomic, transcriptional, and proteomic levels. We detected 18 out of 22 members of the DNA repair system on a protein level. We found that abundance of the respective mRNAs is less than one per cell. We studied transcriptional response of DNA repair genes of M. gallisepticum at stress conditions including heat, osmotic, peroxide stresses, tetracycline and ciprofloxacin treatment, stationary phase and heat stress in stationary phase.
  
  
  CONCLUSIONS
  Based on comparative genomic study, we determined that the DNA repair system M. gallisepticum includes a sufficient set of proteins to provide a cell with functional nucleotide and base excision repair and mismatch repair. We identified SOS-response in M. gallisepticum on ciprofloxacin, which is a known SOS-inducer, tetracycline and heat stress in the absence of established regulators. Heat stress was found to be the strongest SOS-inducer. We found that upon transition to stationary phase of culture growth transcription of DNA repair genes decreases dramatically. Heat stress does not induce SOS-response in a stationary phase.
authors.affiliation: Research Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a, Moscow 119992, Russian Federation. augorbachev@gmail.com.
authors.forename: Alexey Y
authors.initials: AY
authors.lastname: Gorbachev
authors.forename: Gleb Y
authors.initials: GY
authors.lastname: Fisunov
authors.forename: Mark
authors.initials: M
authors.lastname: Izraelson
authors.forename: Darya V
authors.initials: DV
authors.lastname: Evsyutina
authors.forename: Pavel V
authors.initials: PV
authors.lastname: Mazin
authors.forename: Dmitry G
authors.initials: DG
authors.lastname: Alexeev
authors.forename: Olga V
authors.initials: OV
authors.lastname: Pobeguts
authors.forename: Tatyana N
authors.initials: TN
authors.lastname: Gorshkova
authors.forename: Sergey I
authors.initials: SI
authors.lastname: Kovalchuk
authors.forename: Dmitry E
authors.initials: DE
authors.lastname: Kamashev
authors.forename: Vadim M
authors.initials: VM
authors.lastname: Govorun
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004260:DNA Repair; D045643:DNA Repair Enzymes / Q000032:analysis / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000633:toxicity; D045686:Mycoplasma gallisepticum / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D045522:Recombinases / Q000235:genetics / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D013696:Temperature; D059467:Transcriptome / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D045522:Recombinases; D006861:Hydrogen Peroxide; D045643:DNA Repair Enzymes