Trichome

POLI
Available structures
PDBOrtholog search: PDBe RCSB
Identifiers
AliasesPOLI, RAD30B, RAD3OB, polymerase (DNA) iota, DNA polymerase iota
External IDsOMIM: 605252 MGI: 1347081 HomoloGene: 5209 GeneCards: POLI
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_007195

NM_001136090
NM_001289515
NM_001289516
NM_011972

RefSeq (protein)
Location (UCSC)n/aChr 18: 70.64 – 70.66 Mb
PubMed search[2][3]
Wikidata
View/Edit HumanView/Edit Mouse

DNA polymerase iota is an enzyme that in humans is encoded by the POLI gene.[4] It is found in higher eukaryotes, and is believed to have arisen from a gene duplication from Pol η. Pol ι, is a Y family polymerase that is involved in translesion synthesis. It can bypass 6-4 pyrimidine adducts and abasic sites and has a high frequency of wrong base incorporation. Like many other Y family polymerases Pol ι, has low processivity, a large DNA binding pocket and doesn't undergo conformational changes when DNA binds. These attributes are what allow Pol ι to carry out its task as a translesion polymerase. Pol ι only uses Hoogsteen base pairing, during DNA synthesis, it will add adenine opposite to thymine in the syn conformation and can add both cytosine and thymine in the anti conformation across guanine, which it flips to the syn conformation.

Xeroderma pigmentosum variant[edit]

Xeroderma pigmentosum variant (XPV) cells lack DNA polymerase eta (η)[5]. Instead these cells use DNA polymerase iota (ι)[5]. Exposure of XPV cells to UV light causes a very high frequency and unique specturm of UV-induced mutations that can ultimately lead to malignant transformation[5].

References[edit]

  1. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000038425 - Ensembl, May 2017
  2. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  3. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ Frank EG, Woodgate R (Aug 2007). "Increased catalytic activity and altered fidelity of human DNA polymerase iota in the presence of manganese". J Biol Chem. 282 (34): 24689–96. doi:10.1074/jbc.M702159200. PMID 17609217.
  5. ^ a b c Wang Y, Woodgate R, McManus TP, Mead S, McCormick JJ, Maher VM. Evidence that in xeroderma pigmentosum variant cells, which lack DNA polymerase eta, DNA polymerase iota causes the very high frequency and unique spectrum of UV-induced mutations. Cancer Res. 2007 Apr 1;67(7):3018-26. doi: 10.1158/0008-5472.CAN-06-3073. PMID: 17409408

Further reading[edit]

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