Nucleic Acids Research, 1987, Vol. 15, No. 24 10249-10265
© 1987
Articles |
Characterization of a stable, major DNA polymerase 
species devoid of DNA primase activity
Department of Zoology Iowa State University, Ames, IA 50011-3223, USA
+To whom correspondence should be addressed
Received September 21, 1987. Revised November 10, 1987. Accepted November 10, 1987.
We have purified from Xenopus laevis ovaries a major DNA polymerase 
species that lacked DNA primase activity. This primase-devoid DNA polymerase species exhibited the same sensitivity as the DNA polymerase DNA primase to BuAdATP and BuPdGTP, nucleotide analogs capable of distinguishing between DNA polymerase 
and DNA polymerase DNA primase . The primase-devoid DNA polymerase species also lacked significant nuclease activity indicative of the -like (rather than -like) nature of the DNA polymerase. Using a poly(dT) template, the primase-devoid DNA polymerase species elongated an oligo(rA10) primer up to 51-fold more effectively than an oligo(dA10 primer. In direct contrast, the DNA polymerase DNA primase complex showed only a 4.6-fold preference for oligoribonucleotide primers at the same template/primer ratio. The catalytic differences between the two DNA polymerase a species were most dramatic at a template/primer ratio of 300. The primase-devoid DNA polymerase a species was found at high levels throughout oocyte and embryonic development. This suggests that the primase-devoid DNA polymerase species could play a physiological role during DNA chain elongation in vivo, even if it is chemically related to DNA polymerase DNA primase .
*Formerly at: Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA