[en] Bacteriophage-T4 UV endonuclease nicks the C(3')-O-P bond 3' to AP (apurinic or apyrimidinic) sites by a beta-elimination reaction. The breakage of this bond is sometimes followed by the nicking of the C(5')-O-P bond 5' to the AP site, leaving a 3'-phosphate end; delta-elimination is proposed as a mechanism to explain this second reaction. The AP site formed when this enzyme acts on a pyrimidine dimer in a polynucleotide chain undergoes the same nicking reactions. Micrococcus luteus UV endonuclease also nicks the C(3')-O-P bond 3' to AP sites by a beta-elimination reaction. No subsequent delta-elimination was observed, but this might be due to the presence of 2-mercaptoethanol in the enzyme preparation.
Disciplines :
Human health sciences: Multidisciplinary, general & others
Sente, Béatrice ; Université de Liège - ULiège > Département des sciences précliniques BP > Biochimie générale, humaine et pathologique
Verly, Walter ; Relations académiques et scientifiques (Sciences) ; Belgium
Language :
English
Title :
Bacteriophage-T4 and Micrococcus luteus UV endonucleases are not endonucleases but beta-elimination and sometimes beta delta-elimination catalysts.
Alternative titles :
[fr] Les endonucléases UV de Bacteriophage-T4 et de Micrococcus luteus ne sont pas des endonucléases mais des catalyseurs de bêta-élimination et parfois de bêta-delta-élimination.
