1skr
From Proteopedia
T7 DNA Polymerase Complexed To DNA Primer/Template and ddATP
Structural highlights
Function[THIO_ECOLI] Participates in various redox reactions through the reversible oxidation of its active center dithiol to a disulfide and catalyzes dithiol-disulfide exchange reactions. [DPOL_BPT7] Replicates viral genomic DNA. Non-processive DNA polymerase that achieves processivity by binding to host thioredoxin (TrxA). This interaction increases the rate of dNTP incorporation to yield a processivity of approximately 800 nucleotides (nt) per binding event. Interacts with DNA helicase gp4 to coordinate nucleotide polymerization with unwinding of the DNA. The leading strand is synthesized continuously while synthesis of the lagging strand requires the synthesis of oligoribonucleotides by the primase domain of gp4.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedUltraviolet-induced DNA damage poses a lethal block to replication. To understand the structural basis for this, we determined crystal structures of a replicative DNA polymerase from bacteriophage T7 in complex with nucleotide substrates and a DNA template containing a cis-syn cyclobutane pyrimidine dimer (CPD). When the 3' thymine is the templating base, the CPD is rotated out of the polymerase active site and the fingers subdomain adopts an open orientation. When the 5' thymine is the templating base, the CPD lies within the polymerase active site where it base-pairs with the incoming nucleotide and the 3' base of the primer, while the fingers are in a closed conformation. These structures reveal the basis for the strong block of DNA replication that is caused by this photolesion. Nucleotide insertion opposite a cis-syn thymine dimer by a replicative DNA polymerase from bacteriophage T7.,Li Y, Dutta S, Doublie S, Bdour HM, Taylor JS, Ellenberger T Nat Struct Mol Biol. 2004 Aug;11(8):784-90. Epub 2004 Jul 4. PMID:15235589[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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