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PDBsum entry 2pol
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Nucleotidyltransferase
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PDB id
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2pol
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Three-Dimensional structure of the beta subunit of e. Coli DNA polymerase III holoenzyme: a sliding DNA clamp.
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Authors
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X.P.Kong,
R.Onrust,
M.O'Donnell,
J.Kuriyan.
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Ref.
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Cell, 1992,
69,
425-437.
[DOI no: ]
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PubMed id
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Abstract
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The crystal structure of the beta subunit (processivity factor) of DNA
polymerase III holoenzyme has been determined at 2.5 A resolution. A dimer of
the beta subunit (M(r) = 2 x 40.6 kd, 2 x 366 amino acid residues) forms a
ring-shaped structure lined by 12 alpha helices that can encircle duplex DNA.
The structure is highly symmetrical, with each monomer containing three domains
of identical topology. The charge distribution and orientation of the helices
indicate that the molecule functions by forming a tight clamp that can slide on
DNA, as shown biochemically. A potential structural relationship is suggested
between the beta subunit and proliferating cell nuclear antigen (PCNA, the
processivity factor), and the gene 45
protein of the bacteriophage T4 DNA polymerase.
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