Translesion synthesis by translesion polymerases is a conserved mechanism of DNA damage tolerance. In bacteria, DinB enzymes are the widely distributed promutagenic translesion polymerases. The role of DinBs in mycobacterial mutagenesis was unclear until recent studies revealed a role for mycobacterial DinB1 in substitution and frameshift mutagenesis, overlapping with that of translesion polymerase DnaE2. encodes two additional DinBs (DinB2 and DinB3) and encodes DinB2, but the roles of these polymerases in mycobacterial damage tolerance and mutagenesis is unknown. The biochemical properties of DinB2, including facile utilization of ribonucleotides and 8-oxo-guanine, suggest that DinB2 could be a promutagenic polymerase. Here, we examine the effects of DinB2 and DinB3 overexpression in mycobacterial cells. We demonstrate that DinB2 can drive diverse substitution mutations conferring antibiotic resistance. DinB2 induces frameshift mutations in homopolymeric sequences, both in vitro and in vivo. DinB2 switches from less to more mutagenic in the presence of manganese in vitro. This study indicates that DinB2 may contribute to mycobacterial mutagenesis and antibiotic resistance acquisition in combination with DinB1 and DnaE2.
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http://dx.doi.org/10.7554/eLife.83094 | DOI Listing |
Elife
May 2023
Immunology Program, Sloan Kettering Institute, New York, United States.
Translesion synthesis by translesion polymerases is a conserved mechanism of DNA damage tolerance. In bacteria, DinB enzymes are the widely distributed promutagenic translesion polymerases. The role of DinBs in mycobacterial mutagenesis was unclear until recent studies revealed a role for mycobacterial DinB1 in substitution and frameshift mutagenesis, overlapping with that of translesion polymerase DnaE2.
View Article and Find Full Text PDFMicrobiology (Reading)
May 2022
Department of Microbiology, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata 700054, India.
A previous study reported that the (Msm) protein MSMEG_2295 is a repressor controlling the expression of several genes, including that for MSMEG_5125, a putative isoprenoid binding protein belonging to the YceI family, and DinB2, a DNA damage repair enzyme. This repressor is encoded by the first gene of the operon that also expresses the gene for DinB2. Targeted inhibition of MSMEG_5125 using CRISPRi technology resulted in a significant loss of Msm's respiratory activity and viability.
View Article and Find Full Text PDFMicrobiology (Reading)
October 2021
Department of Microbiology, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata-700054, India.
MSMEG_2295 is a TetR family protein encoded by the first gene of a (Msm) operon that expresses the gene for DinB2 (MSMEG_2294), a translesion DNA repair enzyme. We have carried out investigations to understand its function by performing DNA binding studies and gene knockout experiments. We found that the protein binds to a conserved inverted repeat sequence located upstream of the operon and several other genes.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 2020
Immunology Program, Sloan Kettering Institute, New York, NY 10065;
Oxidative damage to DNA is a threat to the genomic integrity and coding accuracy of the chromosomes of all living organisms. Guanine is particularly susceptible to oxidation, and 8-oxo-dG (OG), when produced in situ or incorporated by DNA polymerases, is highly mutagenic due to mispairing with adenine. In many bacteria, defense against OG depends on MutT enzymes, which sanitize OG in the nucleotide pool, and the MutM/Y system, which counteracts OG in chromosomal DNA.
View Article and Find Full Text PDFAcc Chem Res
June 2018
State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence on Molecular Synthesis , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , China.
Natural products typically are small molecules produced by living organisms. These products possess a wide variety of biological activities and thus have historically played a critical role in medicinal chemistry and chemical biology either as chemotherapeutic agents or as useful tools. Natural products are not synthesized for use by human beings; rather, living organisms produce them in response to various biochemical processes and environmental concerns, both internal and external.
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