Ross C A, Harris W J
Biochem J. 1978 Apr 1;171(1):241-9. doi: 10.1042/bj1710241.
The properties of three DNA polymerase species A, B and C, purified from Chlamydomonas reinhardii were compared. DNA polymerases A and B have Km values with respect to deoxyribonucleoside triphosphates of 19 micron and 3 micron respectively. DNA polymerase A is most active with activated DNA, but will also use native DNA and synthetic RNA and DNA templates with DNA primers. DNA polymerase B is also most active with activated DNA, but will use denatured DNA and synthetic DNA templates. It is inactive with RNA templates. DNA polymerase B is completely inactive in the presence of 100 micron-heparin, which has no effect on DNA polymerase A activity. Heparin dissociates DNA polymerase B into subunits that are still catalytically active, but which heparin inhibited. DNA polymerase B possesses deoxyribonuclease activity that is inhibited by 5 micron-heparin, suggesting that the deoxyribonuclease is an integral part of the DNA polymerase moiety. DNA polymerase A is devoid of nuclease activity. DNA polymerase C is similar to DNA polymerase B in all these properties, though it is more active with RNA primers and has greater heat-sensitivity.
对从莱茵衣藻中纯化得到的三种DNA聚合酶A、B和C的特性进行了比较。DNA聚合酶A和B对脱氧核糖核苷三磷酸的Km值分别为19微摩尔和3微摩尔。DNA聚合酶A对活化DNA活性最高，但也能利用天然DNA以及带有DNA引物的合成RNA和DNA模板。DNA聚合酶B对活化DNA也最具活性，但会利用变性DNA和合成DNA模板。它对RNA模板无活性。在100微摩尔肝素存在的情况下，DNA聚合酶B完全无活性，而肝素对DNA聚合酶A的活性没有影响。肝素可将DNA聚合酶B解离成仍具催化活性但被肝素抑制的亚基。DNA聚合酶B具有脱氧核糖核酸酶活性，该活性被5微摩尔肝素抑制，这表明脱氧核糖核酸酶是DNA聚合酶部分的一个组成部分。DNA聚合酶A没有核酸酶活性。DNA聚合酶C在所有这些特性上与DNA聚合酶B相似，不过它对RNA引物的活性更高，且热敏感性更强。
