DnaE Polymerase: Difference between revisions
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[http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=protein&id=16128177 protein sequence E.coli K12] | [http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=protein&id=16128177 protein sequence E.coli K12] | ||
--[[User:ThomasHuber|ThomasHuber]] 09:38, 19 February 2008 (EST) | --[[User:ThomasHuber|ThomasHuber]] 09:38, 19 February 2008 (EST) | ||
[http://oregonstate.edu/instruct/bb492/lectures/DNAII.html Polymerase III] | [http://oregonstate.edu/instruct/bb492/lectures/DNAII.html Polymerase III] | ||
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--[[User:Benjamin|Benjamin]] 09:22, 26 February 2008 (EST) | --[[User:Benjamin|Benjamin]] 09:22, 26 February 2008 (EST) | ||
== Introduction to Polymerase III == | |||
Pol III core is a 1:1:1 heterotrimer of the α polymerase, ε 3'-5' proofreading exonuclease, and θ subunits (39,40). The α subunit (encoded by dnaE) contains the DNA polymerase activity, incorporating 8 nucleotides per second (ntd/s) similar to Pol III core (20 ntds/s) | Pol III core is a 1:1:1 heterotrimer of the α polymerase, ε 3'-5' proofreading exonuclease, and θ subunits (39,40). The α subunit (encoded by dnaE) contains the DNA polymerase activity, incorporating 8 nucleotides per second (ntd/s) similar to Pol III core (20 ntds/s) |
Latest revision as of 23:41, 25 February 2008
--ThomasHuber 09:38, 19 February 2008 (EST)
--Brendan 10:39, 19 February 2008 (EST)
Comparative Analysis of Eubacterial DNA Polymerase III Alpha Subunits
--Benjamin 09:22, 26 February 2008 (EST)
Introduction to Polymerase III
Pol III core is a 1:1:1 heterotrimer of the α polymerase, ε 3'-5' proofreading exonuclease, and θ subunits (39,40). The α subunit (encoded by dnaE) contains the DNA polymerase activity, incorporating 8 nucleotides per second (ntd/s) similar to Pol III core (20 ntds/s)
The replisome is composed of the following:
1) 2 DNA Pol III enzymes, made up of α, ε and θ subunits.
o the α subunit has polymerization activity. o the ε subunit has proofreading activity. o the θ subunit stimulates the ε subunit's proofreading.
2) 2 β units which act as sliding DNA clamps, they keep the polymerase bound to the DNA.
3) 2 τ units which connect the 2 DNA Pol III enzymes.
4) 1 γ unit which acts as a clamp loader for the lagging strand Okazaki fragments, helping the two β subunits to form a unit and bind to DNA. The γ unit is made up of 5 γ subunits.