POL32/YJR043C Summary Help

Standard Name POL32 1
Systematic Name YJR043C
Alias REV5 2
Feature Type ORF, Verified
Description Third subunit of DNA polymerase delta; involved in chromosomal DNA replication; required for error-prone DNA synthesis in the presence of DNA damage and processivity; forms a complex with Rev3p, Rev7p and Pol31p; interacts with Hys2p, PCNA (Pol30p), and Pol1p (3, 4, 5 and see Summary Paragraph)
Name Description POLymerase 1
Chromosomal Location
ChrX:517513 to 516461 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All POL32 GO evidence and references
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 4 genes
Classical genetics
Large-scale survey
725 total interaction(s) for 281 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 10
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 4
  • Biochemical Activity: 1
  • Co-purification: 2
  • Reconstituted Complex: 15
  • Two-hybrid: 9

Genetic Interactions
  • Dosage Growth Defect: 2
  • Dosage Lethality: 3
  • Negative Genetic: 310
  • Phenotypic Enhancement: 15
  • Phenotypic Suppression: 14
  • Positive Genetic: 15
  • Synthetic Growth Defect: 209
  • Synthetic Lethality: 82
  • Synthetic Rescue: 31

Expression Summary
Length (a.a.) 350
Molecular Weight (Da) 40,309
Isoelectric Point (pI) 8.56
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrX:517513 to 516461 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1053 517513..516461 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 | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000003804

DNA polymerase delta is involved in many aspects of DNA metabolism, including various types of repair, and both leading and lagging strand elongation. In Saccharomyces cerevisiae, the DNA polymerase delta complex consists of three subunits of 125, 55, and 40 kDa (1). An additional small fourth subunit is found in the enzymes from fission yeast and human (6, 7, 8). Hydrodynamic studies of S. cerevisiae DNA polymerase delta have revealed the three-subunit complex to be highly elongated, with an unusual sedimentation constant (9). This deviation from globularity of the entire three-subunit complex could be attributed to the extremely elongated structure of the third subunit, Pol32p (4). Indeed, Pol32p with a calculated molecular mass of 40 kDa migrates as a 55-kDa protein by SDS-PAGE, while 55-kDa Pol31p migrates as a 58-kDa protein (1).

The catalytic subunit and the second subunit of DNA polymerase delta, Pol3p and Pol31p, are highly conserved in eukaryotes (4). These genes are also essential in both budding and fission yeast (4). In contrast, the third subunit, Pol32p, is not essential, and shows an extreme divergence at the primary amino acid level, such that in Saccharomyces paradoxus, which shows a mean amino acid sequence identity with S. cerevisiae of over 90% for all proteins, only 82% sequence identity is observed for Pol32p (4). For the Pol3p and Pol31p subunits, sequence identity is 96% and 93%, respectively (10). The essential functionalities of Pol32p reside in a small amino-terminal domain, not much larger than that necessary to specify its interaction with Pol31p (4). Compared to fission yeast and human, only one motif is highly conserved in Pol32p, the consensus PCNA (proliferating cell nuclear antigen)-binding motif QXX(L/I)XXFF at the extreme carboxy-terminus (4).

pol32delta mutants show severe defects in DNA replication, repair, and mutagenesis (1). Further, the combination of pol32delta with conditional mutations in POL3, POL31, or POL30 (PCNA) is lethal (4).

Last updated: 2005-09-15 Contact SGD

References cited on this page View Complete Literature Guide for POL32
1) Gerik KJ, et al.  (1998) Characterization of the two small subunits of Saccharomyces cerevisiae DNA polymerase delta. J Biol Chem 273(31):19747-55
2) Lawrence CW, et al.  (1985) New mutations affecting induced mutagenesis in yeast. Mutat Res 150(1-2):211-6
3) Huang ME, et al.  (2002) Pol32, a subunit of Saccharomyces cerevisiae DNA polymerase delta, suppresses genomic deletions and is involved in the mutagenic bypass pathway. Genetics 160(4):1409-22
4) Johansson E, et al.  (2004) The Pol32 subunit of DNA polymerase delta contains separable domains for processive replication and proliferating cell nuclear antigen (PCNA) binding. J Biol Chem 279(3):1907-15
5) Makarova AV, et al.  (2012) A four-subunit DNA polymerase ? complex containing Pol d accessory subunits is essential for PCNA-mediated mutagenesis. Nucleic Acids Res 40(22):11618-26
6) Zuo S, et al.  (1997) DNA polymerase delta isolated from Schizosaccharomyces pombe contains five subunits. Proc Natl Acad Sci U S A 94(21):11244-9
7) Liu L, et al.  (2000) Identification of a fourth subunit of mammalian DNA polymerase delta. J Biol Chem 275(25):18739-44
8) Podust VN, et al.  (2002) Reconstitution of human DNA polymerase delta using recombinant baculoviruses: the p12 subunit potentiates DNA polymerizing activity of the four-subunit enzyme. J Biol Chem 277(6):3894-901
9) Johansson E, et al.  (2001) Structure of DNA polymerase delta from Saccharomyces cerevisiae. J Biol Chem 276(47):43824-8
10) Cliften PF, et al.  (2001) Surveying Saccharomyces genomes to identify functional elements by comparative DNA sequence analysis. Genome Res 11(7):1175-86