Скачать с ютуб Discovering mutagenic DNA polymerase IV in E. coli в хорошем качестве

Discovering mutagenic DNA polymerase IV in E. coli

OTHER VIDEOS YOU MIGHT LIKE: • Discovery of primase: a puzzle piece in understanding DNA synthesis -    • Discovery of primase: a puzzle piece ...   • The Shine-Dalgarno sequence: The ribosome’s time to Shine -    • The Shine-Dalgarno sequence: The ribo...   • Recoding genomes: The hip new trend in synthetic biology -    • Recoding genomes: The hip new trend i...   How do cells repair damaged DNA? And how do spontaneous mutations arise? Understanding the mechanisms of DNA damage and repair allows us to control vital elements of molecular biology, including development of cancer and antibiotic resistance. Tech advancements of the late 20th century allowed purification of more cellular proteins. This enabled an acceleration in scientific research which totally revolutionized our understanding of mutagenesis! It was 1999 when Wagner and his team of researchers in Tokyo proved that E. coli DinB protein was actually a mutagenic polymerase. Previously, DinB was thought to just alter Pol III activity, so this was a big change! In this video, we explore the different aspects of Wagner’s experiments, as well as some earlier research to set the stage. Together, this forms a great foundation for understanding the behaviour and impacts of Pol IV. Wagner and his team showed that Pol IV has no proofreading (exonuclease) mechanism, which clearly underlies its increased rate of mutagenesis. When encountering singular mismatched nucleotides, Pol IV was shown to frequently create -1 frameshift mutations. Targeted mutagenesis of UmuC family homologous regions destroyed DinB’s polymerase activity, hinting the rest of the family could be polymerases too! In the years that followed, a flurry of research detailed the polymerase activity of every protein in the UmuC family. So many new polymerases were discovered that a new class emerged – the Y-family polymerases! Different polymerases show different lesion specificity, filling alternate roles in the coordinated response to DNA damage (and environmental stress). Complex interactions between polymerases and other cellular proteins massively alters mutagenic effects on the cell. Pol IV is the most highly conserved Y-family polymerase across all domains of life, so understanding its behaviour is clearly a vital piece of the puzzle. Creator: Simone Ogg References: The Saccharomyces cerevisiae RAD30 gene, a homologue of Escherichia coli dinB and umuC, is DNA damage inducible and functions in a novel error-free postreplication repair mechanism. J P McDonald, A S Levine, R Woodgate. Genetics. 1997 Dec;147(4):1557-68. doi: 10.1093/genetics/147.4.1557. Requirement of DNA polymerase activity of yeast Rad30 protein for its biological function. Johnson RE, Prakash S, Prakash L. J Biol Chem. 1999 Jun 4;274(23):15975-7. doi: 10.1074/jbc.274.23.15975. dinP, a new gene in Escherichia coli, whose product shows similarities to UmuC and its homologues. Ohmori H, Hatada E, Qiao Y, Tsuji M, Fukuda R. Mutat Res. 1995 Jun;347(1):1-7. doi: 10.1016/0165-7992(95)90024-1. A single residue unique to DinB-like proteins limits formation of the polymerase IV multiprotein complex in Escherichia coli. Tiziana M Cafarelli, Thomas J Rands, Ryan W Benson, Pamela A Rudnicki, Ida Lin, Veronica G Godoy. J Bacteriol. 2013 Mar;195(6):1179-93. doi: 10.1128/JB.01349-12. Stationary-phase mutation in the bacterial chromosome: recombination protein and DNA polymerase IV dependence. Bull HJ, Lombardo MJ, Rosenberg SM. Proc Natl Acad Sci U S A. 2001 Jul 17;98(15):8334-41. doi: 10.1073/pnas.151009798. Discontinuities in the DNA synthesized in an excision-defective strain of Escherichia coli following ultraviolet irradiation. Rupp WD, Howard-Flanders P. J Mol Biol. 1968 Jan 28;31(2):291-304. doi: 10.1016/0022-2836(68)90445-2. SOS repair hypothesis: phenomenology of an inducible DNA repair which is accompanied by mutagenesis. Radman M. Basic Life Sci. 1975;5A:355-67. doi: 10.1007/978-1-4684-2895-7_48. The dinB gene encodes a novel E. coli DNA polymerase, DNA pol IV, involved in mutagenesis.Wagner J, Gruz P, Kim SR, Yamada M, Matsui K, Fuchs RP, Nohmi T. Mol Cell. 1999 Aug;4(2):281-6. doi: 10.1016/s1097-2765(00)80376-7. UmuD'(2)C is an error-prone DNA polymerase, Escherichia coli pol V. Tang M, Shen X, Frank EG, O'Donnell M, Woodgate R, Goodman MF. Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8919-24. doi:10.1073/pnas.96.16.8919. PMID: 10430871 Single-strand-specific exonucleases prevent frameshift mutagenesis by suppressing SOS induction and the action of DinB/DNA polymerase IV in growing cells. Hersh MN, Morales LD, Ross KJ, Rosenberg SM. J Bacteriol. 2006 Apr;188(7):2336-42. doi: 10.1128/JB.188.7.2336-2342.2006. UmuD and RecA directly modulate the mutagenic potential of the Y family DNA polymerase DinB. Godoy VG, Jarosz DF, Simon SM, Abyzov A, Ilyin V, Walker GC. Mol Cell. 2007 Dec 28;28(6):1058-70. doi: 10.1016/j.molcel.2007.10.025.