3suo

RB69 DNA Polymerase (Y567A) Ternary Complex with dTTP Opposite 2AP (GC rich sequence)RB69 DNA Polymerase (Y567A) Ternary Complex with dTTP Opposite 2AP (GC rich sequence)

Structural highlights 3suo is a 3 chain structure with sequence from Enterobacteria phage rb69. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: , NonStd Res: , Related: 3sq2, 3sq4, 3sun, 3sup, 3suq Gene: 43 (Enterobacteria phage RB69) Activity: DNA-directed DNA polymerase, with EC number 2.7.7.7 Resources: FirstGlance, OCA, RCSB, PDBsum Function [DPOL_BPR69] This polymerase possesses two enzymatic activities: DNA synthesis (polymerase) and an exonucleolytic activity that degrades single stranded DNA in the 3'- to 5'-direction. Publication Abstract from PubMed The adenine base analogue 2-aminopurine (2AP) is a potent base substitution mutagen in prokaryotes because of its enhanceed ability to form a mutagenic base pair with an incoming dCTP. Despite more than 50 years of research, the structure of the 2AP-C base pair remains unclear. We report the structure of the 2AP-dCTP base pair formed within the polymerase active site of the RB69 Y567A-DNA polymerase. A modified wobble 2AP-C base pair was detected with one H-bond between N1 of 2AP and a proton from the C4 amino group of cytosine and an apparent bifurcated H-bond between a proton on the 2-amino group of 2-aminopurine and the ring N3 and O2 atoms of cytosine. Interestingly, a primer-terminal region rich in AT base pairs, compared to GC base pairs, facilitated dCTP binding opposite template 2AP. We propose that the increased flexibility of the nucleotide binding pocket formed in the Y567A-DNA polymerase and increased "breathing" at the primer-terminal junction of A+T-rich DNA facilitate dCTP binding opposite template 2AP. Thus, interactions between DNA polymerase residues with a dynamic primer-terminal junction play a role in determining base selectivity within the polymerase active site of RB69 DNA polymerase. Structure of the 2-Aminopurine-Cytosine Base Pair Formed in the Polymerase Active Site of the RB69 Y567A-DNA Polymerase.,Reha-Krantz LJ, Hariharan C, Subuddhi U, Xia S, Zhao C, Beckman J, Christian T, Konigsberg W Biochemistry. 2011 Nov 22;50(46):10136-49. Epub 2011 Oct 28. PMID:22023103 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA polymerase

spinqualitylabelsall models 3suo, resolution 2.23Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image