REPAIRtoire - a database of DNA repair pathways

Welcome! Click here to login or here to register.
Home
Proteins
DNA damage
Diseases
Homologs
Pathways
Keywords
Publications
Draw a picture
 
Search
 
Links
Help
Contact





Bujnicki Lab Homepage

"Misinsertion and bypass of thymine-thymine dimers by human DNA polymerase iota."

Tissier A, Frank EG, McDonald JP, Iwai S, Hanaoka F, Woodgate R



Published Oct. 2, 2000 in EMBO J volume 19 .

Pubmed ID: 11013228

Abstract:
Human DNA polymerase iota (pol(iota)) is a recently discovered enzyme that exhibits extremely low fidelity on undamaged DNA templates. Here, we show that poliota is able to facilitate limited translesion replication of a thymine-thymine cyclobutane pyrimidine dimer (CPD). More importantly, however, the bypass event is highly erroneous. Gel kinetic assays reveal that pol(iota) misinserts T or G opposite the 3' T of the CPD approximately 1.5 times more frequently than the correct base, A. While pol(iota) is unable to extend the T.T mispair significantly, the G.T mispair is extended and the lesion completely bypassed, with the same efficiency as that of the correctly paired A. T base pair. By comparison, pol(iota) readily misinserts two bases opposite a 6-4 thymine-thymine pyrimidine-pyrimidone photoproduct (6-4PP), but complete lesion bypass is only a fraction of that observed with the CPD. Our data indicate, therefore, that poliota possesses the ability to insert nucleotides opposite UV photoproducts as well as to perform unassisted translesion replication that is likely to be highly mutagenic.


This publication refers to following REPAIRtoire entries:

Proteins


Last modification of this entry: Oct. 6, 2010

Add your own comment!

There is no comment yet.
Welcome stranger! Click here to login or here to register.
Valid HTML 4.01! This site is Emacs powered. Made with Django.