We have analyzed the effects of temeperature-sensitivity (ts)-conferring mutations in the Saccharomyces cerevisiae DNA polymerase I-encoding gene on cell growth, in vivo DNA synthesis, intrachromosomal gene conversion and pop-out recombination. Also, we have identified the molecular defect responsible for the ts phenotype. Two mutant alleles (cdc17-1, cdc17-2) were originally identified as cell-cycle mutations, while a third mutation (hpr3) was found during a genetic screening for mutants with a hyper-recombination phenotype. Both cdc17-2 and hpr3 cells complete one round of cell division and DNA replication after shift to nonpermissive temperature, before being arrestedas a dumbbell-shaped cells. Conversely, the cdc17-1 mutation immediately blocks growth and DNA synthesis at 37°C. No substantial difference was observed in the frequency of intrachromosomal gene conversion and pop-out recombination events, when hpr3 and cdc17-1 were compared to the previously characterized pol1-1 mutant. These two frequencies were ten- to 30-fold above wild-type level at semipermissive temperature. In each mutant, a single bp substitution, causing the replacement of Gly residues by either Asp (cdc17-1, cdc17-2) or Glu (hpr3) in yeast DNA polymerase I is responsible for the ts phenotype.
Nucleotide sequence and characterization of temperature-sensitive pol1 mutants of Saccharomyces cerevisiae / G. Lucchini, M. Muzi Falconi, A. Pizzagalli, A. Aguilera, H.L. Klein, P. Plevani. - In: GENE. - ISSN 0378-1119. - 90:1(1990 May 31), pp. 99-104.
|Titolo:||Nucleotide sequence and characterization of temperature-sensitive pol1 mutants of Saccharomyces cerevisiae|
MUZI FALCONI, MARCO (Secondo)
PLEVANI, PAOLO (Ultimo)
|Parole Chiave:||cloning; DNA polymerase; gene conversion; pop-out recombination; primase; recombinant DNA|
|Settore Scientifico Disciplinare:||Settore BIO/11 - Biologia Molecolare|
|Data di pubblicazione:||31-mag-1990|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/0378-1119(90)90444-V|
|Appare nelle tipologie:||01 - Articolo su periodico|