title: DNA lesion alters global conformational dynamics of Y-family DNA polymerase during catalysis.
abstract: A major product of oxidative damage to DNA, 8-oxo-7,8-dihydro-2'-deoxyguanine (8-oxoG), can lead to genomic mutations if it is bypassed unfaithfully by DNA polymerases in vivo. However, our pre-steady-state kinetic studies show that DNA polymerase IV (Dpo4), a prototype Y-family enzyme from Sulfolobus solfataricus, can bypass 8-oxoG both efficiently and faithfully. For the first time, our stopped-flow FRET studies revealed that a DNA polymerase altered its synchronized global conformational dynamics in response to a DNA lesion. Relative to nucleotide incorporation into undamaged DNA, three of the four domains of Dpo4 undertook different conformational transitions during 8-oxoG bypass and the subsequent extension step. Moreover, the rapid translocation of Dpo4 along DNA induced by nucleotide binding was significantly hindered by the interactions between the embedded 8-oxoG and Dpo4 during the extension step. These results unprecedentedly demonstrate that a Y-family DNA polymerase employs different global conformational dynamics when replicating undamaged and damaged DNA.
authors.affiliation: Biophysics Program, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Maxwell
authors.forename: Cuiling
authors.initials: C
authors.lastname: Xu
authors.forename: Zucai
authors.initials: Z
authors.lastname: Suo
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002384:Catalysis; D004249:DNA Damage / Q000502:physiology; D019951:DNA Polymerase beta / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D006147:Guanine / Q000031:analogs & derivatives / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D048229:Sulfolobus solfataricus / Q000201:enzymology* / Q000235:genetics*
chemical_list: C453560:7,8-dihydro-8-oxoguanine; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D006147:Guanine; D019951:DNA Polymerase beta