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

"Endonucleolytic function of MutLalpha in human mismatch repair."

Kadyrov FA, Dzantiev L, Constantin N, Modrich P



Pubmed ID: 16873062

Abstract:
Half of hereditary nonpolyposis colon cancer kindreds harbor mutations that inactivate MutLalpha (MLH1*PMS2 heterodimer). MutLalpha is required for mismatch repair, but its function in this process is unclear. We show that human MutLalpha is a latent endonuclease that is activated in a mismatch-, MutSalpha-, RFC-, PCNA-, and ATP-dependent manner. Incision of a nicked mismatch-containing DNA heteroduplex by this four-protein system is strongly biased to the nicked strand. A mismatch-containing DNA segment spanned by two strand breaks is removed by the 5'-to-3' activity of MutSalpha-activated exonuclease I. The probable endonuclease active site has been localized to a PMS2 DQHA(X)(2)E(X)(4)E motif. This motif is conserved in eukaryotic PMS2 homologs and in MutL proteins from a number of bacterial species but is lacking in MutL proteins from bacteria that rely on d(GATC) methylation for strand discrimination in mismatch repair. Therefore, the mode of excision initiation may differ in these organisms.


This publication refers to following REPAIRtoire entries:

DNA states
Proteins
Repair activities


Last modification of this entry: Dec. 10, 2009

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.