Disruption of the Bacteriophage T4 Mre11 Dimer Interface Reveals a Two-state Mechanism for Exonuclease Activity

dc.contributor.author Albrecht, Dustin
dc.contributor.author Herdendorf, Timothy
dc.contributor.author Nelson, Scott
dc.contributor.author Nelson, Scott
dc.contributor.department Biochemistry, Biophysics and Molecular Biology
dc.date 2018-02-17T15:05:37.000
dc.date.accessioned 2020-06-29T23:47:23Z
dc.date.available 2020-06-29T23:47:23Z
dc.date.copyright Sun Jan 01 00:00:00 UTC 2012
dc.date.issued 2012-07-01
dc.description.abstract <p>The Mre11-Rad50 (MR) complex is a central player in DNA repair and is implicated in the processing of DNA ends caused by double strand breaks. Recent crystal structures of the MR complex suggest that several conformational rearrangements occur during its ATP hydrolysis cycle. A comparison of the Mre11 dimer interface from these structures suggests that the interface is dynamic in nature and may adopt several different arrangements. To probe the functional significance of the Mre11 dimer interface, we have generated and characterized a dimer disruption Mre11 mutant (L101D-Mre11). Although L101D-Mre11 binds to Rad50 and dsDNA with affinity comparable with the wild-type enzyme, it does not activate the ATP hydrolysis activity of Rad50, suggesting that the allosteric communication between Mre11 and Rad50 has been interrupted. Additionally, the dsDNA exonuclease activity of the L101D-MR complex has been reduced by 10-fold under conditions where processive exonuclease activity is required. However, we unexpectedly found that under steady state conditions, the nuclease activity of the L101D-MR complex is significantly greater than that of the wild-type complex. Based on steady state and single-turnover nuclease assays, we have assigned the rate-determining step of the steady state nuclease reaction to be the productive assembly of the complex at the dsDNA end. Together, our data suggest that the Mre11 dimer interface adopts at least two different states during the exonuclease reaction.</p>
dc.description.comments <p>This article is from <em>Journal of Biological Chemistry</em> 287 (2012): 31371, doi: <a href="http://dx.doi.org/10.1074/jbc.M112.392316" target="_blank">10.1074/jbc.M112.392316</a>. Posted with permission.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/bbmb_ag_pubs/68/
dc.identifier.articleid 1077
dc.identifier.contextkey 8372465
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath bbmb_ag_pubs/68
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/10801
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/bbmb_ag_pubs/68/2012_NelsonSW_DisruptionBacteriophageT4.pdf|||Sat Jan 15 01:28:44 UTC 2022
dc.source.uri 10.1074/jbc.M112.392316
dc.subject.disciplines Biochemistry, Biophysics, and Structural Biology
dc.subject.disciplines Molecular Biology
dc.subject.keywords DNA Enzymes
dc.subject.keywords DNA Recombination
dc.subject.keywords DNA Repair
dc.subject.keywords DNA-Protein Interaction
dc.subject.keywords Enzyme Kinetics
dc.subject.keywords DNA Exonuclease
dc.subject.keywords Double Strand Break Repair
dc.subject.keywords MR Complex
dc.title Disruption of the Bacteriophage T4 Mre11 Dimer Interface Reveals a Two-state Mechanism for Exonuclease Activity
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication 6570190c-e045-441a-a9bf-59c716840114
relation.isOrgUnitOfPublication c70f85ae-e0cd-4dce-96b5-4388aac08b3f
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