2atq

RB69 single-stranded DNA binding protein-DNA polymerase fusion

spinqualitylabelsall models 2atq, resolution 3.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2atq is a 2 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: GDP, ZN Gene: 43 (Enterobacteria phage RB69), gp32 (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. 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 PubMed In vivo, replicative DNA polymerases are made more processive by their interactions with accessory proteins at the replication fork. Single-stranded DNA binding protein (SSB) is an essential protein that binds tightly and cooperatively to single-stranded DNA during replication to remove adventitious secondary structures and protect the exposed DNA from endogenous nucleases. Using information from high resolution structures and biochemical data, we have engineered a functional chimeric enzyme of the bacteriophage RB69 DNA polymerase and SSB with substantially increased processivity. Fusion of RB69 DNA polymerase with its cognate SSB via a short six amino acid linker increases affinity for primer-template DNA by sixfold and subsequently increases processivity by sevenfold while maintaining fidelity. The crystal structure of this fusion protein was solved by a combination of multiwavelength anomalous diffraction and molecular replacement to 3.2 A resolution and shows that RB69 SSB is positioned proximal to the N-terminal domain of RB69 DNA polymerase near the template strand channel. The structural and biochemical data suggest that SSB interactions with DNA polymerase are transient and flexible, consistent with models of a dynamic replisome during elongation. Structure and enzymatic properties of a chimeric bacteriophage RB69 DNA polymerase and single-stranded DNA binding protein with increased processivity.,Sun S, Geng L, Shamoo Y Proteins. 2006 Oct 1;65(1):231-8. PMID:16881051 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA polymerase

Proteopedia Page Contributors and Editors (what is this?)

OCA