The DNA repair repertoire of Mycobacterium smegmatis FenA includes the incision of DNA 5' flaps and the removal of 5' adenylylated products of aborted nick ligation Journal Article
| Authors: | Uson, M. L.; Ghosh, S.; Shuman, S. |
| Article Title: | The DNA repair repertoire of Mycobacterium smegmatis FenA includes the incision of DNA 5' flaps and the removal of 5' adenylylated products of aborted nick ligation |
| Abstract: | We characterize Mycobacterium smegmatis FenA as a manganese-dependent 5'-flap endonuclease homologous to the 5'-exonuclease of DNA polymerase I. FenA incises a nicked 5' flap between the first and second nucleotides of the duplex segment to yield a 1-nucleotide gapped DNA, which is then further resected in dinucleotide steps. Initial FenA cleavage at a Y-flap or nick occurs between the first and second nucleotides of the duplex. However, when the template 3' single strand is eliminated to create a 5'-tailed duplex, FenA incision shifts to between the second and third nucleotides. A double-flap substrate with a mobile junction (mimicking limited strand displacement synthesis during gap repair) is preferentially incised as the 1-nucleotide 3'-flap isomer, with the scissile phosphodiester shifted by one nucleotide versus a static double flap. FenA efficiently removes the 5' App(dN) terminus of an aborted nick ligation reaction intermediate, thereby highlighting FenA as an agent of repair of such lesions, which are formed under a variety of circumstances by bacterial NAD+-dependent DNA ligases and especially by mycobacterial DNA ligases D and C. © 2017 American Society for Microbiology. |
| Keywords: | metabolism; dna repair; biological model; models, biological; enzymology; amino acid sequence; sequence alignment; dna repair enzymes; flap endonuclease; endonuclease; bacterial dna; dna, bacterial; dna ligase; mycobacterium smegmatis; manganese; mycobacteria; endonucleases; enzyme activator; enzyme activators |
| Journal Title: | Journal of Bacteriology |
| Volume: | 199 |
| Issue: | 17 |
| ISSN: | 0021-9193 |
| Publisher: | American Society for Microbiology |
| Date Published: | 2017-09-01 |
| Start Page: | e00304-17 |
| Language: | English |
| DOI: | 10.1128/jb.00304-17 |
| PUBMED: | 28630124 |
| PROVIDER: | scopus |
| PMCID: | PMC5553029 |
| DOI/URL: | |
| Notes: | Article -- Export Date: 5 September 2017 -- Source: Scopus |
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