G:U mismatches resulting from deamination of cytosine are the most common promutagenic lesions occurring in DNA. Uracil is removed in a base-excision repair pathway by uracil DNA-glycosylase (UDG), which excises uracil from both single- and double-stranded DNA. Recently, a biochemically distinct family of DNA repair enzymes has been identified, which excises both uracil and thymine, but only from mispairs with guanine. Crystal structures of the mismatch-specific uracil DNA-glycosylase (MUG) from E. coli, and of a DNA complex, reveal a remarkable structural and functional homology to UDGs despite low sequence identity. Details of the MUG structure explain its thymine DNA-glycosylase activity and the specificity for G:U/T mispairs, which derives from direct recognition of guanine on the complementary strand.
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http://dx.doi.org/10.1016/s0092-8674(00)80904-6 | DOI Listing |
Plant Biotechnol J
January 2025
Institute of Crop Sciences/National Nanfan Research Institute, Chinese Academy of Agricultural Sciences (CAAS), and Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Sanya, China.
Sci Rep
January 2025
Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, N-7491, Trondheim, Norway.
The cytotoxic mechanisms of thymidylate synthase inhibitors, such as the multitarget antifolate pemetrexed, are not yet fully understood. Emerging evidence indicates that combining pemetrexed with histone deacetylase inhibitors (HDACi) may enhance therapeutic efficacy in non-small cell lung cancer (NSCLC). To explore this further, A549 NSCLC cells were treated with various combinations of pemetrexed and the HDACi MS275 (Entinostat), and subsequently assessed for cell viability, cell cycle changes, and genotoxic markers.
View Article and Find Full Text PDFACS Synth Biol
January 2025
Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P. R. China.
The fusion expression of deoxyribonucleic acid (DNA) replication-related proteins with nucleotide deaminase enzymes promotes random mutations in bacterial genomes, thereby increasing genetic diversity among the population. Most previous studies have focused on cytosine deaminase, which produces only C → T mutations, significantly limiting the variety of mutation types. In this study, we developed a fusion expression system by combining DnaG (RNA primase) with adenine deaminase TadA-8e (DnaG-TadA) in , which is capable of rapidly introducing A → G mutations into the genome, resulting in a 664-fold increase in terms of mutation rate.
View Article and Find Full Text PDFACS Synth Biol
January 2025
The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
targeted mutagenesis technologies are the basis for the continuous directed evolution of specific proteins. Here, an efficient mutagenesis system (CgMutaT7) for continuous evolution of the targeted gene in was developed. First, cytosine deaminase and uracil-DNA glycosylase inhibitor were sequentially fused to T7 RNA polymerase using flexible linkers to build the CgMutaT7 system, which introduces mutations in targeted regions controlled by the T7 promoter.
View Article and Find Full Text PDFTalanta
November 2024
College of Life Sciences, Northwest University, Xi'an, 710069, China. Electronic address:
Straightforward genotyping can provide timely diagnostic information for diseases prevention and treatment. Taking advantages of speediness and convenience, although numerous genotyping strategies combined loop-mediated isothermal amplification (LAMP) and lateral flow have been reported to satisfy the demand of point-of-care test, the false positive result caused by aerosol and primer dimer as an innate conflict seriously limits their practical application. In this study, both aerosol and primer dimer as extrinsic and intrinsic inducements respectively are first broken through at one stroke based on an integrated immunochromatographic biosensor.
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