title: RNA-primed DNA synthesis: specific catalysis by HeLa cell DNA polymerase alpha.
abstract: We have analyzed and compared the responses of the three major HeLa cell DNA polymerases (alpha, beta, and gamma) to a HeLa DNA template with short RNA or DNA primers hybridized to it. Only DNA polymerase alpha is able to synthesize DNA covalently bonded to the RNA primer via a 3' yields 5' phosphodiester bond.  32P transfer experiments showed that all combinations of ribo- and deoxyribonucleotides are represented in the RNA-DNA linkages but their distribution is nonrandom. The RNA-DNA linked molecules base-paired to a HeLa DNA template strand represent a possible "natural" in vitro primer-template for DNA polymerases and can be extended by all three DNA polymerases (alpha, beta, and gamma). These findings indicate that DNA polymerases beta and gamma are capable of DNA-primed but not RNA-PRIMED DNA synthesis, while DNA polymerase alpha is capable of both RNA-primed and DAN-primed DNA synthesis.
mesh_terms: D001483:Base Sequence; D004247:DNA; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D004277:DNA, Single-Stranded / Q000096:biosynthesis*; D005260:Female; D006367:HeLa Cells / Q000201:enzymology*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D007700:Kinetics; D009693:Nucleic Acid Hybridization; D009711:Nucleotides / Q000378:metabolism; D012313:RNA; D013698:Templates, Genetic
chemical_list: D004273:DNA, Neoplasm; D004277:DNA, Single-Stranded; D007527:Isoenzymes; D009711:Nucleotides; D012313:RNA; D004247:DNA; D004254:DNA Nucleotidyltransferases