DnaE Polymerase: Difference between revisions

From MDWiki
Jump to navigationJump to search
No edit summary
No edit summary
 
Line 1: Line 1:
[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]
Line 13: Line 11:
--[[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

protein sequence E.coli K12

--ThomasHuber 09:38, 19 February 2008 (EST)

Polymerase III

--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.