TY - JOUR
T1 - The mitochondrial DNA polymerase βfrom Crithidia fasciculata has 5′-deoxyribose phosphate (dRP) lyase activity but is deficient in the release of dRP
AU - Saxowsky, Tina T.
AU - Matsumoto, Yoshihiro
AU - Englund, Paul T.
PY - 2002/10/4
Y1 - 2002/10/4
N2 - DNA polymerase β (pol β) has long been described as a nuclear enzyme involved in DNA repair. A pol β from the trypanosomatid parasite Crithidia fasciculata, however, is the first example of a mitochondrial enzyme of this type. The mammalian nuclear enzyme functions not only as a nucleotidyl transferase but also has a dRP lyase activity that cleaves 5′-deoxyribose phosphate (dRP) groups from DNA, thus contributing to two consecutive steps of the base excision repair pathway. We find that the mitochondrial pol β also has dRP lyase activity. Interestingly, the Km of this enzyme for a dRP-containing substrate is similar to that for the rat enzyme, but its kcat is very low. This difference is due to a deficiency of the mitochondrial enzyme in the release of dRP from the enzyme following its cleavage from the DNA.
AB - DNA polymerase β (pol β) has long been described as a nuclear enzyme involved in DNA repair. A pol β from the trypanosomatid parasite Crithidia fasciculata, however, is the first example of a mitochondrial enzyme of this type. The mammalian nuclear enzyme functions not only as a nucleotidyl transferase but also has a dRP lyase activity that cleaves 5′-deoxyribose phosphate (dRP) groups from DNA, thus contributing to two consecutive steps of the base excision repair pathway. We find that the mitochondrial pol β also has dRP lyase activity. Interestingly, the Km of this enzyme for a dRP-containing substrate is similar to that for the rat enzyme, but its kcat is very low. This difference is due to a deficiency of the mitochondrial enzyme in the release of dRP from the enzyme following its cleavage from the DNA.
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U2 - 10.1074/jbc.M206654200
DO - 10.1074/jbc.M206654200
M3 - Article
C2 - 12151410
AN - SCOPUS:0037020226
SN - 0021-9258
VL - 277
SP - 37201
EP - 37206
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 40
ER -