期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1974
卷号：71
期号：2
页码：578-582
DOI：10.1073/pnas.71.2.578
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Five distinct forms of DNA polymerase (deoxynucleosidetriphosphate: DNA deoxynucleotidyltransferase, EC 2.7.7.7 ) were separated from extracts of mouse myeloma MOPC-104E using a fractionation procedure based upon sequential ion-exchange column chromatography. The enzymes were characterized according to sedimentation behavior, subcellular localization, chromatographic behavior on hydroxyapatite columns, and reaction properties. The results indicate that myeloma contains two enzymes that appear to correspond to well characterized DNA polymerases found in many other mammalian tissues, a 6S DNA polymerase localized in the cytoplasmic supernatant fraction, and a lower molecular weight (2-3S) DNA polymerase. Also present were a second 6S DNA polymerase localized exclusively in the nuclear fraction and a 6-8S DNA polymerase localized in the cytoplasmic membrane fraction. The enzyme in the cytoplasmic membrane fraction, which accounted for the predominant activity in the myeloma, was active with poly(rA){middle dot}(dT)12-18 as template-primer, but not with activated calf thymus DNA. The detection of this distinct 6-8S membrane-bound DNA polymerase is of particular interest.
