Publication Date:
2009-12-17
Description:
How living systems detect the presence of genotoxic damage embedded in a million-fold excess of undamaged DNA is an unresolved question in biology. Here we have captured and structurally elucidated a base-excision DNA repair enzyme, MutM, at the stage of initial encounter with a damaged nucleobase, 8-oxoguanine (oxoG), nested within a DNA duplex. Three structures of intrahelical oxoG-encounter complexes are compared with sequence-matched structures containing a normal G base in place of an oxoG lesion. Although the protein-DNA interfaces in the matched complexes differ by only two atoms-those that distinguish oxoG from G-their pronounced structural differences indicate that MutM can detect a lesion in DNA even at the earliest stages of encounter. All-atom computer simulations show the pathway by which encounter of the enzyme with the lesion causes extrusion from the DNA duplex, and they elucidate the critical free energy difference between oxoG and G along the extrusion pathway.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2951314/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2951314/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Qi, Yan -- Spong, Marie C -- Nam, Kwangho -- Banerjee, Anirban -- Jiralerspong, Sao -- Karplus, Martin -- Verdine, Gregory L -- CA100742/CA/NCI NIH HHS/ -- GM030804/GM/NIGMS NIH HHS/ -- GM044853/GM/NIGMS NIH HHS/ -- GM047467/GM/NIGMS NIH HHS/ -- P01 GM047467/GM/NIGMS NIH HHS/ -- P01 GM047467-100006/GM/NIGMS NIH HHS/ -- P30 EB009998/EB/NIBIB NIH HHS/ -- R01 CA100742/CA/NCI NIH HHS/ -- R01 CA100742-06A1/CA/NCI NIH HHS/ -- R01 GM044853/GM/NIGMS NIH HHS/ -- R01 GM044853-18/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2009 Dec 10;462(7274):762-6. doi: 10.1038/nature08561.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Graduate Program in Biophysics, Harvard Medical School, Boston, Massachusetts 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20010681" target="_blank"〉PubMed〈/a〉
Keywords:
Biocatalysis
;
Computer Simulation
;
Crystallography, X-Ray
;
*DNA Damage
;
*DNA Repair
;
DNA-Formamidopyrimidine Glycosylase/genetics/*metabolism
;
Genome, Bacterial/genetics
;
Geobacillus stearothermophilus/*enzymology/genetics
;
Guanine/*analogs & derivatives/metabolism
;
Models, Biological
;
Models, Molecular
;
Molecular Dynamics Simulation
;
Mutation/genetics
;
Thermodynamics
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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