Details

Autor(en) / Beteiligte

• Sidorenko, Julia
• Jatsenko, Tatjana
• Saumaa, Signe
• Teras, Riho
• Tark-Dame, Mariliis
• Hõrak, Rita
• Kivisaar, Maia

Titel

Involvement of specialized DNA polymerases Pol II, Pol IV and DnaE2 in DNA replication in the absence of Pol I in Pseudomonas putida

Ist Teil von

• Mutation research, 2011-09, Vol.714 (1), p.63-77

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2011

Quelle

MEDLINE

Beschreibungen/Notizen

• ► Absence of Pol I elevates mutation frequency in Pseudomonas putida. ► Reduction of reactive oxygen species suppresses growth defects of Pol I mutant. ► Specialized DNA polymerases partially substitute Pol I functions. ► Presence of Pol I affects the occurrence of Pol II- and Pol IV-dependent mutations. ► DnaE2-catalyzed DNA replication in Pol I mutant bacteria is stimulated by UV light. The majority of bacteria possess a different set of specialized DNA polymerases than those identified in the most common model organism Escherichia coli. Here, we have studied the ability of specialized DNA polymerases to substitute Pol I in DNA replication in Pseudomonas putida. Our results revealed that P. putida Pol I-deficient cells have severe growth defects in LB medium, which is accompanied by filamentous cell morphology. However, growth of Pol I-deficient bacteria on solid rich medium can be restored by reduction of reactive oxygen species in cells. Also, mutants with improved growth emerge rapidly. Similarly to the initial Pol I-deficient P. putida, its adapted derivatives express a moderate mutator phenotype, which indicates that DNA replication carried out in the absence of Pol I is erroneous both in the original Pol I-deficient bacteria and the adapted derivatives. Analysis of the spectra of spontaneous Rif r mutations in P. putida strains lacking different DNA polymerases revealed that the presence of specialized DNA polymerases Pol II and Pol IV influences the frequency of certain base substitutions in Pol I-proficient and Pol I-deficient backgrounds in opposite ways. Involvement of another specialized DNA polymerase DnaE2 in DNA replication in Pol I-deficient bacteria is stimulated by UV irradiation of bacteria, implying that DnaE2-provided translesion synthesis partially substitutes the absence of Pol I in cells containing heavily damaged DNA.