Structural Insights Into DNA Repair by RNase T—An Exonuclease Processing 3′ End of Structured DNA in Repair Pathways

摘要: DNA repair mechanisms are essential for preservation of genome integrity. However, it is not clear how selected and processed at broken ends by exonucleases during pathways. Here we show that the DnaQ-like exonuclease RNase T critical Escherichia coli resistance to various DNA-damaging agents UV radiation. specifically trims 3′ end structured DNA, including bulge, bubble, Y-structured can work with Endonuclease V restore deaminated base in an inosine-containing heteroduplex DNA. Crystal structure analyses further reveal recognizes bulge inserting a phenylalanine into as result blunt-end be digested T. In contrast, homodimeric interacts different binding mode via single protomer so overhang trimmed closely duplex region. Our data suggest likely processes bubble V–dependent repair, whereas UV-induced other This study thus provides mechanistic insights thousands 3′-end processing.