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 (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 spectrum of UV-induced mutations that can ultimately lead to malignant transformation.[5]
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PDB gallery
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1t3n: Structure of the catalytic core of DNA polymerase Iota in complex with DNA and dTTP
1zet: X-ray data do not support hoogsteen base-pairing during replication by human polymerase iota
2alz: Ternary Complex of hPoli with DNA and dCTP
2dpi: Ternary complex of hPoli with DNA and dCTP
2dpj: structure of hPoli with DNA and dTTP
2fll: Ternary complex of human DNA polymerase iota with DNA and dTTP
2fln: binary complex of catalytic core of human DNA polymerase iota with DNA (template A)
2flp: Binary complex of the catalytic core of human DNA polymerase iota with DNA (template G)
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