DukeSpace will be down for maintenance at 9:15 AM EDT on Tuesday, July 29. Expected downtime is 20 minutes or less.

Show simple item record

dc.contributor.advisor Beese, Lorena S en_US
dc.contributor.author Wang, Weina en_US
dc.date.accessioned 2012-05-25T20:22:03Z
dc.date.available 2014-05-15T04:30:05Z
dc.date.issued 2012 en_US
dc.identifier.uri http://hdl.handle.net/10161/5607
dc.description Dissertation en_US
dc.description.abstract <p>High-fidelity DNA polymerases achieve remarkable accuracy by exhibiting exquisite nucleotide substrate selection mechanisms. DNA polymerases not only discriminate highly against base-pair mismatches, but also show a high degree of selectivity for the correct sugar moiety deoxyribonucleotide over ribo- and dideoxy-nucleotides. Although DNA polymerase is highly accurate, some base-pair mismatches are still incorporated at low frequency, leading to spontaneous mutagenesis. Mechanisms for both accurate and mutagenic DNA replication have been subjected to intense solution studies and speculations over half a decade. However, structural understanding of both processes are still very limited due to the lack of crystal structures of DNA polymerase bound with incorrect nucleotide substrates especially at the insertion step prior to chemistry which accounts for the majority of the intrinsic specificity of the polymerase. </p><p>In this dissertation, X-ray crystallographic analyses were performed using a model system for studying replication fidelity, a thermostable strain of Bacillus DNA polymerase I large fragment (Bacillus fragment, BF) that catalyzes replication in crystals. A series of high-resolution crystal structures of BF polymerase variants and DNA duplex with mismatches, incorrect sugar substrates, and cognate base pairs bound at various fidelity filter sites on the polymerase surface were determined. By comparing structures of non-cognate base pairs with those of cognate base pairs captured under the same experimental condition, a unified picture of substrate selectivity by DNA polymerase for both mutagenic and accurate replication process has emerged.</p> en_US
dc.subject Biochemistry en_US
dc.title Structural Mechanisms of Accurate and Mutagenic DNA Replication en_US
dc.type Dissertation en_US
dc.department Biochemistry en_US
duke.embargo.months 24 en_US

Files in this item

This item appears in the following Collection(s)

Show simple item record