The POL1 and POL3 DNA Synthesis Genes in Fission Yeast Schizosaccharomyces pombe
We isolated and sequenced the S. pombe genes encoding the catalytic subunits of DNA polymerases a (POL1) and δ (POL3) by sequence homology with S. cerevisiae gene probes. Both genes contain a short intron in the 5’ region of the open reading frame. About 300 bp 5’ to POL1 is located the RPL7b gene which encodes a predicted ribosomal protein and is divergently transcribed. The codon usage of POL1 and POL3 is in agreement with both genes being weakly expressed; on the contrary, RPL7b shows a codon usage characteristic of highly expressed genes. The pol α and pol δ predicted peptides were compared with known sequences of DNA polymerases. Both polypeptides contain the seven conserved amino acid blocks diagnostic of a super-family of DNA polymerases. Moreover, pol a shows additional blocks conserved only in α-type eukaryotic DNA polymerases known to date, and pol δ shows a high overall identity percentage with the homologous S. cerevisiae protein indicating an important structural inter-species conservation. We also raised antibodies against two fusion proteins containing E. coli β-galactosidase and part of either pol α or pol δ. These antibodies inhibit in vitro two distinct DNA polymerase activities present in S. pombe cell extracts.
KeywordsZinc Codon Agarose Cysteine Polypeptide
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- Guthrie C, Fink GR (eds) (1991) Guide to yeast genetics and molecular biology. Methods in Enzymology 194. Academic Press Inc. San Diego CaliforniaGoogle Scholar
- Harlow E, Lane D (1988) Antibodies. Cold Spring Harbor Laboratory Press Cold Spring Harbor New YorkGoogle Scholar
- Nasim A, Young P, Johnson BF (eds) (1989) Molecular Biology of the Fission Yeast. Academic Press Inc. San Diego CaliforniaGoogle Scholar
- Pignède G, Bouvier D, De Recondo A-M, Baldacci G (1991) Characterization of the POL3 gene product from S. pombe indicates inter-species conservation of the catalytic subunit of DNA polymerase delta. J Mol Biol in pressGoogle Scholar
- Russel P (1989) Gene cloning and expression in fission yeast. In Molecular Biology of the Fission Yeast (Nasim A, Young P, Johnson BF eds) 243–271. Academic Press Inc. San Diego CaliforniaGoogle Scholar
- Sambrook J, Fritsch EF, Maniatis T (1989) Molecular Cloning. Cold Spring Harbor Laboratory Press Cold Spring Harbor New YorkGoogle Scholar
- Wong SW, Wahl AF, Yuan P-M, Arai N, Pearson BE, Arai K-I, Korn D, Hunkapiller MW, Wang TSF (1988) Human DNA polymerase alpha gene expression is cell proliferation dependant and its primary structure is similar to both prokaryotic and eukaryotic replicative DNA polymerases. EMBO J 7:37–47PubMedGoogle Scholar