POL30/YBR088C Summary Help

Standard Name POL30 1
Systematic Name YBR088C
Feature Type ORF, Verified
Description Proliferating cell nuclear antigen (PCNA); functions as the sliding clamp for DNA polymerase delta; may function as a docking site for other proteins required for mitotic and meiotic chromosomal DNA replication and for DNA repair (2 and see Summary Paragraph)
Name Description POLymerase
Gene Product Alias PCNA
Chromosomal Location
ChrII:425766 to 424990 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All POL30 GO evidence and references
  View Computational GO annotations for POL30
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 138 genes
Classical genetics
reduction of function
Large-scale survey
reduction of function
466 total interaction(s) for 221 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 25
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 30
  • Biochemical Activity: 18
  • Co-crystal Structure: 6
  • Co-fractionation: 2
  • Co-purification: 1
  • FRET: 8
  • PCA: 1
  • Protein-peptide: 1
  • Reconstituted Complex: 40
  • Two-hybrid: 36

Genetic Interactions
  • Dosage Growth Defect: 2
  • Dosage Lethality: 2
  • Dosage Rescue: 17
  • Negative Genetic: 111
  • Phenotypic Enhancement: 30
  • Phenotypic Suppression: 12
  • Positive Genetic: 35
  • Synthetic Growth Defect: 29
  • Synthetic Lethality: 31
  • Synthetic Rescue: 28

Expression Summary
Length (a.a.) 258
Molecular Weight (Da) 28,916
Isoelectric Point (pI) 4.26
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrII:425766 to 424990 | 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..777 425766..424990 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 SGDIDS000000292

PCNA (proliferating cell nuclear antigen, encoded by POL30) is a highly conserved homotrimeric ring-shaped complex that encircles DNA and functions as a sliding clamp and processivity factor for replicative DNA polymerases (3). PCNA is loaded by the replication factor C complex (RFC) onto primer-template sites of DNA and directs the replication machinery to the replication fork (4, 5). PCNA is also required for the establishment of sister chromatid cohesion (6), multiple forms of DNA repair, and various postreplication DNA processing reactions (7, 8), recruiting proteins involved in cell cycle control, nucleotide excision repair, mismatch repair and base excision repair (9, 10).

PCNA is subject to differential modification and functional targeting by both ubiquitin (Ubi4p) and SUMO (Smt3p), which channel PCNA to distinct functional pathways and regulate its roles in DNA replication and postreplication repair (8). PCNA has a single ubiquitination site (lysine 164), which is also the major SUMO acceptor site, although there is an additional, minor sumoylation site at lysine 127 (11, 12). PCNA is mono- and polyubiquitinated following DNA damage (13, 8), which is critical for cell survival as it facilitates the bypass of replication-blocking lesions (11, 12). Mono-ubiquitination of PCNA by Rad6p and Rad18p results in error-prone repair and involves the translesion synthesis polymerases eta (RAD30) and zeta (REV3, REV7), while polyubiquitination by Rad5p, Mms2p, and Ubc13p causes stalled replication forks to initiate error-free DNA repair (12, 8).

In contrast to ubiquitin, SUMO modification of PCNA is not induced by DNA damage (8). PCNA sumoylation on lysine 164 occurs in a Ubc9p-dependent manner in both normal and damaged cells during S phase, and functions to regulate normal DNA replication (8). SUMO modification of PCNA inhibits its ubiquitination and DNA repair functions (8), and recruits the helicase Hpr5p to prevent homologous recombination during S phase (11, 13, 14). Mutation of the ubiquitination and sumoylation sites in PCNA results in sensitivity to DNA damaging agents (7).

PCNA interacts with MSH (MutS Homolog), MLH (MutL Homolog), and ECO1 proteins both in S. cerevisiae and human (ESCO2), typically via their amino-terminal ends (5, 6, 15, 16, 17, 18, 19, 20). The prokaryotic homolog of PCNA is the beta-clamp processivity factor, and its interaction with E. coli polymerase IV is required for spontaneous and DNA damage-induced mutagenesis (21, 22).

Last updated: 2007-06-05 Contact SGD

References cited on this page View Complete Literature Guide for POL30
1) Bauer GA and Burgers PM  (1990) Molecular cloning, structure and expression of the yeast proliferating cell nuclear antigen gene. Nucleic Acids Res 18(2):261-5
2) Tsurimoto T  (1999) PCNA binding proteins. Front Biosci 4():D849-58
3) Paunesku T, et al.  (2001) Proliferating cell nuclear antigen (PCNA): ringmaster of the genome. Int J Radiat Biol 77(10):1007-21
4) Hingorani MM and O'Donnell M  (2000) Sliding clamps: a (tail)ored fit. Curr Biol 10(1):R25-9
5) Marti TM, et al.  (2002) DNA mismatch repair and mutation avoidance pathways. J Cell Physiol 191(1):28-41
6) Moldovan GL, et al.  (2006) PCNA controls establishment of sister chromatid cohesion during S phase. Mol Cell 23(5):723-32
7) Watts FZ  (2006) Sumoylation of PCNA: Wrestling with recombination at stalled replication forks. DNA Repair (Amst) 5(3):399-403
8) Matunis MJ  (2002) On the road to repair: PCNA encounters SUMO and ubiquitin modifications. Mol Cell 10(3):441-2
9) Maga G and Hubscher U  (2003) Proliferating cell nuclear antigen (PCNA): a dancer with many partners. J Cell Sci 116(Pt 15):3051-60
10) Warbrick E  (2000) The puzzle of PCNA's many partners. Bioessays 22(11):997-1006
11) Hoege C, et al.  (2002) RAD6-dependent DNA repair is linked to modification of PCNA by ubiquitin and SUMO. Nature 419(6903):135-41
12) Stelter P and Ulrich HD  (2003) Control of spontaneous and damage-induced mutagenesis by SUMO and ubiquitin conjugation. Nature 425(6954):188-91
13) Papouli E, et al.  (2005) Crosstalk between SUMO and ubiquitin on PCNA is mediated by recruitment of the helicase Srs2p. Mol Cell 19(1):123-33
14) Pfander B, et al.  (2005) SUMO-modified PCNA recruits Srs2 to prevent recombination during S phase. Nature 436(7049):428-33
15) Johnson RE, et al.  (1996) Evidence for involvement of yeast proliferating cell nuclear antigen in DNA mismatch repair. J Biol Chem 271(45):27987-90
16) Umar A, et al.  (1996) Requirement for PCNA in DNA mismatch repair at a step preceding DNA resynthesis. Cell 87(1):65-73
17) Chen C, et al.  (1999) Saccharomyces cerevisiae pol30 (proliferating cell nuclear antigen) mutations impair replication fidelity and mismatch repair. Mol Cell Biol 19(11):7801-15
18) Clark AB, et al.  (2000) Functional interaction of proliferating cell nuclear antigen with MSH2-MSH6 and MSH2-MSH3 complexes. J Biol Chem 275(47):36498-501
19) Flores-Rozas H, et al.  (2000) Proliferating cell nuclear antigen and Msh2p-Msh6p interact to form an active mispair recognition complex. Nat Genet 26(3):375-8
20) Kleczkowska HE, et al.  (2001) hMSH3 and hMSH6 interact with PCNA and colocalize with it to replication foci. Genes Dev 15(6):724-36
21) Lenne-Samuel N, et al.  (2002) The processivity factor beta controls DNA polymerase IV traffic during spontaneous mutagenesis and translesion synthesis in vivo. EMBO Rep 3(1):45-9
22) Friedberg EC, et al.  (2002) Specialized DNA polymerases, cellular survival, and the genesis of mutations. Science 296(5573):1627-30