Polynucleotide recognition by DNA alpha-polymerase.
In a survey of template-primer preference of a mouse myeloma DNA alpha-polymerase, the fastest rate of DNA synthesis was with poly(dT) as template and (rA)24 as primer. Such a preference for poly(dT).oligo(rA) was not observed with other DNA polymerases of mouse origin. DNA synthesis in this system resulted in formation of oligo(dA) chains, not template-length poly(dA); thus, the average enzyme molecule bound to a poly(dT).(rA)24 complex and initiated a new oligo(dA) chain many times during the incubation. Binding experiments revealed that the alpha-polymerase had high affinity for poly(dT). Although the alpha-polymerase did not bind to poly(dl) and failed to replicate it inreactions with a base pair complementary primer, poly(dl) was replicated after a (dT) block had been grafted to its 3'-end and the oligo(rA) primer had been added. In similar experiments, the (dT) block was found to be much more effective than other 3'-terminal blocks in promoting replication of denatured calf thymus DNA. The results indicate that specific base sequences may regulate initiation of DNA syntehsis by this alpha-polymerase.
D002460:Cell Line; D004257:DNA Polymerase II / Q000378:metabolism*; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D009101:Multiple Myeloma / Q000201:enzymology; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D013379:Substrate Specificity; D013698:Templates, Genetic
D004277:DNA, Single-Stranded; D012313:RNA; D004257:DNA Polymerase II; D004259:DNA-Directed DNA Polymerase