POL12/YBL035C Summary Help

Standard Name POL12
Systematic Name YBL035C
Feature Type ORF, Verified
Description B subunit of DNA polymerase alpha-primase complex; required for initiation of DNA replication during mitotic and premeiotic DNA synthesis; also functions in telomere capping and length regulation (1, 2, 3 and see Summary Paragraph)
Name Description POLymerase
Chromosomal Location
ChrII:153610 to 151493 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All POL12 GO evidence and references
  View Computational GO annotations for POL12
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 2 genes
Classical genetics
Large-scale survey
reduction of function
136 total interaction(s) for 107 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 34
  • Affinity Capture-RNA: 2
  • Affinity Capture-Western: 4
  • Co-crystal Structure: 1
  • Reconstituted Complex: 5
  • Two-hybrid: 3

Genetic Interactions
  • Dosage Growth Defect: 1
  • Dosage Rescue: 6
  • Negative Genetic: 69
  • Positive Genetic: 4
  • Synthetic Growth Defect: 3
  • Synthetic Lethality: 3
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 705
Molecular Weight (Da) 78,774
Isoelectric Point (pI) 7.04
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrII:153610 to 151493 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1997-01-28
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..2118 153610..151493 2011-02-03 1997-01-28
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000000131

POL12 is an essential gene (4); it encodes the second largest (79kD), or B, subunit of DNA polymerase alpha (5), formerly called DNA polymerase I (6; reviewed in 7, 8; also see 5). The B subunit executes its essential function during the initiation of DNA replication (4). 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 (9), but not for other DNA repair synthesis (10, 11). All four subunits of DNA polymerase alpha are assembled, and can be co-immunoprecipitated, throughout the cell cycle (12). In addition, affinity chromatography detects physical interactions between the polymerase and several other proteins (13), including Spt16p and Pob3p 14. The B subunit (Pol12p) is phosphorylated in a cell cycle dependent manner (15); association with the 167 kD subunit (Pol1p) is necessary for B subunit phosphorylation (12). Like many other genes encoding DNA replication proteins, POL12 is transcribed during late G1 and S phases of the cell cycle (15). The POL12 promoter contains two MluI cell cycle boxes (MCBs) (15), which are bound by the Swi6p-Mbp1p complex (reviewed in 16 17).

Last updated: 1999-05-07 Contact SGD

References cited on this page View Complete Literature Guide for POL12
1) 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
2) Biswas SB, et al.  (2003) Subunit interactions in the assembly of Saccharomyces cerevisiae DNA polymerase alpha. Nucleic Acids Res 31(8):2056-65
3) Grossi S, et al.  (2004) Pol12, the B subunit of DNA polymerase alpha, functions in both telomere capping and length regulation. Genes Dev 18(9):992-1006
4) Foiani M, et al.  (1994) The B subunit of the DNA polymerase alpha-primase complex in Saccharomyces cerevisiae executes an essential function at the initial stage of DNA replication. Mol Cell Biol 14(2):923-33
5) Plevani P, et al.  (1988) The yeast DNA polymerase-primase complex: genes and proteins. Biochim Biophys Acta 951(2-3):268-73
6) Burgers PM, et al.  (1990) Revised nomenclature for eukaryotic DNA polymerases. Eur J Biochem 191(3):617-8
7) Burgers PM  (1998) Eukaryotic DNA polymerases in DNA replication and DNA repair. Chromosoma 107(4):218-27
8) Sugino A  (1995) Yeast DNA polymerases and their role at the replication fork. Trends Biochem Sci 20(8):319-23
9) 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
10) 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
11) 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
12) 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
13) 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
14) 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
15) Foiani M, et al.  (1995) Cell cycle-dependent phosphorylation and dephosphorylation of the yeast DNA polymerase alpha-primase B subunit. Mol Cell Biol 15(2):883-91
16) Koch C and Nasmyth K  (1994) Cell cycle regulated transcription in yeast. Curr Opin Cell Biol 6(3):451-9
17) Breeden L  (1996) Start-specific transcription in yeast. Curr Top Microbiol Immunol 208():95-127