Open AccessThe mode of inhibitory action by pyridoxal 5-phosphate on DNA polymerase-α and -β
Author(s) -
Mieko Oguro,
Hiroshi Nagano,
Yoshitake Mano
Publication year - 1979
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/7.3.727
Subject(s) - dna polymerase , primer (cosmetics) , biology , microbiology and biotechnology , dna clamp , dna polymerase ii , biochemistry , polymerase , dna , dna polymerase beta , dna polymerase i , non competitive inhibition , primase , pyridoxal , pyridoxal phosphate , phosphate , enzyme , dna repair , chemistry , polymerase chain reaction , reverse transcriptase , gene , base excision repair , cofactor , organic chemistry
The kinetics of the inhibition of DNA polymerases-alpha and -beta from sea urchin embryos by pyridoxal 5-phosphate were studied. The inhibition of DNA polymerase-alpha activity by pyridoxal 5-phosphate was competitive with activated DNA but noncompetitive with each deoxynucleoside triphosphate. With poly(dC)-oligo(dG)12-18 as a template-primer, however, the inhibition of DNA polymerase-alpha was competitive with dGTP but noncompetitive with the template-primer. These results suggest that DNA polymerase-alpha interacts with activated DNA and poly(dC)-oligo(dG)12-18 in different ways. The inhibition of DNA polymerase-beta by pyridoxal 5-phosphate was competitive with deoxynucleoside triphosphate using activated DNA as a template-primer and noncompetitive with activated DNA. Using poly(rA)-oligo(dT)12-18 as a template-primer, DNA polymerase-beta activity yielded sigmoid curves against both dTTP and the template-primer concentrations and was inhibited by pyridoxal 5-phosphate noncompetitively with respect to both dTTP and the template-primer. These results indicate that the inhibitory mode of DNA polymerase-alpha by pyridoxal 5-phosphate is different from that of DNA polymerase-beta.