POL1/YNL102W Summary Help

Standard Name POL1 1
Systematic Name YNL102W
Alias CDC17 2 , CRT5 3 , HPR3
Feature Type ORF, Verified
Description Catalytic subunit of the DNA polymerase I alpha-primase complex; required for the initiation of DNA replication during mitotic DNA synthesis and premeiotic DNA synthesis (4, 5, 6 and see Summary Paragraph)
Name Description POLymerase
Chromosomal Location
ChrXIV:430087 to 434493 | ORF Map | GBrowse
Genetic position: -74 cM
Gene Ontology Annotations All POL1 GO evidence and references
  View Computational GO annotations for POL1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 4 genes
Classical genetics
reduction of function
Large-scale survey
reduction of function
152 total interaction(s) for 77 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 28
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 40
  • Biochemical Activity: 2
  • Co-crystal Structure: 2
  • Co-localization: 2
  • Co-purification: 5
  • Reconstituted Complex: 8
  • Two-hybrid: 10

Genetic Interactions
  • Dosage Growth Defect: 1
  • Dosage Lethality: 6
  • Dosage Rescue: 5
  • Negative Genetic: 12
  • Phenotypic Enhancement: 6
  • Phenotypic Suppression: 4
  • Synthetic Growth Defect: 13
  • Synthetic Lethality: 3
  • Synthetic Rescue: 2

Expression Summary
Length (a.a.) 1,468
Molecular Weight (Da) 166,808
Isoelectric Point (pI) 6.14
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXIV:430087 to 434493 | ORF Map | GBrowse
Genetic position: -74 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..4407 430087..434493 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000005046

POL1 is an essential gene (7); it encodes the largest subunit of DNA polymerase alpha (8), formerly called DNA polymerase I (1; reviewed in 5, 9; also see 8). Yeast DNA polymerase alpha comprises four subunits, of MW 167 kD (Pol1p), 79 kD (Pol12p), 62 kD (Pri2p), and 48 kD (Pri1p). Polymerase alpha is required for DNA replication; it is involved both in initiation and in priming Okazaki fragments during lagging strand elongation. It has no associated proofreading exonuclease activity; the two smaller subunits form the primase activity that synthesizes short RNA primers in DNA replication. In yeast, DNA polymerase alpha activity is required for premeiotic DNA replication and sporulation and for double-strand break repair (10), but not for other DNA repair synthesis (11, 12).

Null mutations in POL1 are lethal; temperature sensitive mutants arrest as large budded (dumbbell-shaped) cells with the nucleus at the mother-bud neck. At the restrictive temperature, pol1-1 temperature sensitive cells can complete only a single round of DNA replication and cell division (13, 14, 15, 16). Overexpression of PAK1, which encodes a protein kinase (17), or of PSP1 or PSP2 (18), suppresses pol1 temperature sensitive mutations, while overexpression of RAD24 slows the growth of pol1 mutants (19).

All four subunits of DNA polymerase alpha are assembled and can be coimmunoprecipitated throughout the cell cycle (20). In addition, affinity chromatography detects physical interactions between the polymerase and several other proteins (21), including Spt16p and Pob3p (22). POL1 also interacts genetically with POL32, which encodes a subunit of DNA polymerase delta. Pol1p and Pol32p also interact physically in two-hybrid assays (23). Like many other genes encoding DNA replication proteins, POL1 is transcribed during late G1 and S phases of the cell cycle (24). The POL1 promoter contains two MluI cell cycle boxes (MCBs) (25, 26), which are bound by the Swi6p-Mbp1p complex (reviewed in 27, 28). DNA polymerase alpha is present throughout the cell cycle, however, and neither POL1 transcription nor de novo Pol1p synthesis is required for entrance into S phase (29).

While the S. cerevisiae DNA polymerase alpha shows amino acid sequence similarity with DNA polymerase alpha from S. pombe (30) and human, neither the human nor the S. pombe homologs of POL1 can complement S. cerevisiae pol1 mutants (31).

Last updated: 1999-05-07 Contact SGD

References cited on this page View Complete Literature Guide for POL1
1) Burgers PM, et al.  (1990) Revised nomenclature for eukaryotic DNA polymerases. Eur J Biochem 191(3):617-8
2) Carson, M.J.  (1987) CDC17, the structural gene for DNA polymerase I of yeast: mitotic hyperrecombination and effects on telomere metabolism. Ph.D. thesis
3) Zhou Z and Elledge SJ  (1992) Isolation of crt mutants constitutive for transcription of the DNA damage inducible gene RNR3 in Saccharomyces cerevisiae. Genetics 131(4):851-66
4) Foiani M, et al.  (1996) A meiosis-specific protein kinase, Ime2, is required for the correct timing of DNA replication and for spore formation in yeast meiosis. Mol Gen Genet 253(3):278-88
5) Burgers PM  (1998) Eukaryotic DNA polymerases in DNA replication and DNA repair. Chromosoma 107(4):218-27
6) Gutierrez PJ and Wang TS  (2003) Genomic instability induced by mutations in Saccharomyces cerevisiae POL1. Genetics 165(1):65-81
7) Carson MJ and Hartwell L  (1985) CDC17: an essential gene that prevents telomere elongation in yeast. Cell 42(1):249-57
8) Plevani P, et al.  (1988) The yeast DNA polymerase-primase complex: genes and proteins. Biochim Biophys Acta 951(2-3):268-73
9) Sugino A  (1995) Yeast DNA polymerases and their role at the replication fork. Trends Biochem Sci 20(8):319-23
10) Holmes AM and Haber JE  (1999) Double-strand break repair in yeast requires both leading and lagging strand DNA polymerases. Cell 96(3):415-24
11) Budd ME, et al.  (1989) DNA polymerase I is required for premeiotic DNA replication and sporulation but not for X-ray repair in Saccharomyces cerevisiae. Mol Cell Biol 9(2):365-76
12) Wang Z, et al.  (1993) DNA repair synthesis during base excision repair in vitro is catalyzed by DNA polymerase epsilon and is influenced by DNA polymerases alpha and delta in Saccharomyces cerevisiae. Mol Cell Biol 13(2):1051-8
13) Budd M and Campbell JL  (1987) Temperature-sensitive mutations in the yeast DNA polymerase I gene. Proc Natl Acad Sci U S A 84(9):2838-42
14) Pizzagalli A, et al.  (1988) DNA polymerase I gene of Saccharomyces cerevisiae: nucleotide sequence, mapping of a temperature-sensitive mutation, and protein homology with other DNA polymerases. Proc Natl Acad Sci U S A 85(11):3772-6
15) Lucchini G, et al.  (1990) Nucleotide sequence and characterization of temperature-sensitive pol1 mutants of Saccharomyces cerevisiae. Gene 90(1):99-104
16) Lucchini G, et al.  (1988) Genetic mapping of the Saccharomyces cerevisiae DNA polymerase I gene and characterization of a pol1 temperature-sensitive mutant altered in DNA primase-polymerase complex stability. Mol Gen Genet 212(3):459-65
17) Hovland PG, et al.  (1997) Overexpression of the protein kinase Pak1 suppresses yeast DNA polymerase mutations. Mol Gen Genet 256(1):45-53
18) Formosa T and Nittis T  (1998) Suppressors of the temperature sensitivity of DNA polymerase alpha mutations in Saccharomyces cerevisiae. Mol Gen Genet 257(4):461-8
19) Lydall D and Weinert T  (1997) G2/M checkpoint genes of Saccharomyces cerevisiae: further evidence for roles in DNA replication and/or repair. Mol Gen Genet 256(6):638-51
20) Ferrari M, et al.  (1996) Phosphorylation of the DNA polymerase alpha-primase B subunit is dependent on its association with the p180 polypeptide. J Biol Chem 271(15):8661-6
21) Miles J and Formosa T  (1992) Protein affinity chromatography with purified yeast DNA polymerase alpha detects proteins that bind to DNA polymerase. Proc Natl Acad Sci U S A 89(4):1276-80
22) Wittmeyer J and Formosa T  (1997) The Saccharomyces cerevisiae DNA polymerase alpha catalytic subunit interacts with Cdc68/Spt16 and with Pob3, a protein similar to an HMG1-like protein. Mol Cell Biol 17(7):4178-90
23) Huang ME, et al.  (1999) The Saccharomyces cerevisiae protein YJR043C (Pol32) interacts with the catalytic subunit of DNA polymerase alpha and is required for cell cycle progression in G2/M. Mol Gen Genet 260(6):541-50
24) Verma R, et al.  (1991) Identification and purification of a factor that binds to the Mlu I cell cycle box of yeast DNA replication genes. Proc Natl Acad Sci U S A 88(16):7155-9
25) Gordon CB and Campbell JL  (1991) A cell cycle-responsive transcriptional control element and a negative control element in the gene encoding DNA polymerase alpha in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 88(14):6058-62
26) Pizzagalli A, et al.  (1992) Positive cis-acting regulatory sequences mediate proper control of POL1 transcription in Saccharomyces cerevisiae. Curr Genet 21(3):183-9
27) Koch C and Nasmyth K  (1994) Cell cycle regulated transcription in yeast. Curr Opin Cell Biol 6(3):451-9
28) Breeden L  (1996) Start-specific transcription in yeast. Curr Top Microbiol Immunol 208():95-127
29) Falconi MM, et al.  (1993) De novo synthesis of budding yeast DNA polymerase alpha and POL1 transcription at the G1/S boundary are not required for entrance into S phase. Proc Natl Acad Sci U S A 90(22):10519-23
30) Damagnez V, et al.  (1991) The POL1 gene from the fission yeast, Schizosaccharomyces pombe, shows conserved amino acid blocks specific for eukaryotic DNA polymerases alpha. Mol Gen Genet 226(1-2):182-9
31) Francesconi S, et al.  (1993) In vivo species specificity of DNA polymerase alpha. Mol Gen Genet 241(3-4):457-66