Mouse DNA polymerase alpha-primase terminates and reinitiates DNA synthesis 2-14 nucleotides upstream of C2A1-2(C2-3/T2) sequences on a minute virus of mice DNA template.
The distribution of termination and initiation sites in a 5081-nucleotide minute virus of mice DNA template being copied by a highly purified mouse DNA polymerase alpha-DNA primase complex in the presence of GTP has been examined. The 3'-hydroxyl termini (17 in all) were clustered at six sites that were located 2-14 nucleotides upstream of C2A2C2, C2AC3, or C2A2T2 sequences. When either [alpha-32P]- or [gamma-32P]GTP was included in the DNA polymerase reaction mixtures, nascent DNA became radiolabeled. Analysis of the 32P-labeled material following treatment of the DNA with tobacco acid pyrophosphatase, bacterial alkaline phosphatase, or ribonuclease T1 revealed the presence of oligoribonucleotide chains averaging 5-7 nucleotides long and beginning with 5' GTP residues. Eight presumptive DNA primase initiation sites were located opposite C4 or C5 sequences 3-9 nucleotides upstream of one of the three closely related hexanucleotides C2A2C2, C2AC3, and C2A2T2. RNA-DNA junctions were found 3-10 nucleotides downstream of DNA primase initiation sites. The results indicate that hexanucleotides having the general formula C2A1-2(C2-3/T2), herein referred to as psi, are involved in promoting termination of DNA synthesis and/or de novo initiation of RNA-primed DNA chains by DNA polymerase alpha-primase.
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D004257:DNA Polymerase II / Q000032:analysis / Q000235:genetics*; D019915:DNA Primase; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D005809:Genes, Regulator; D046911:Macromolecular Substances; D051379:Mice; D008970:Molecular Weight; D012316:RNA Nucleotidyltransferases / Q000032:analysis / Q000235:genetics*; D012367:RNA, Viral / Q000096:biosynthesis; D013698:Templates, Genetic
D004279:DNA, Viral; D046911:Macromolecular Substances; D012367:RNA, Viral; D019915:DNA Primase; D012316:RNA Nucleotidyltransferases; D004257:DNA Polymerase II