DNA polymerase iota - Q9UNA4 (POLI_HUMAN)


Protein Feature View of PDB entries mapped to a UniProtKB sequence  

  • Number of PDB entries for Q9UNA4: 38
Error-prone DNA polymerase specifically involved in DNA repair. Plays an important role in translesion synthesis, where the normal high-fidelity DNA polymerases cannot proceed and DNA synthesis stalls. Favors Hoogsteen base-pairing in the active site. Inserts the correct base with high-fidelity opposite an adenosine template. Exhibits low fidelity and efficiency opposite a thymidine template, where it will preferentially insert guanosine. May play a role in hypermutation of immunogobulin genes. Forms a Schiff base with 5'-deoxyribose phosphate at abasic sites, but may not have lyase activity. (data source: UniProt  )
Catalytic Activity

Deoxynucleoside triphosphate + DNAn = diphosphate + DNAn+1.

(data source: UniProt  )
Subunit structure
Interacts with REV1 (By similarity). Interacts with POLH. (data source: UniProt  )
The catalytic core consists of fingers, palm and thumb subdomains, but the fingers and thumb subdomains are much smaller than in high-fidelity polymerases; residues from five sequence motifs of the Y-family cluster around an active site cleft that can accommodate DNA and nucleotide substrates with relaxed geometric constraints, with consequently higher rates of misincorporation and low processivity. (data source: UniProt  )
This protein in other organisms (by gene name):
Organism (common name): Human
Other Gene names: RAD30B
Chromosome Location: chr18:51795916- 51820837
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Data in green originates from UniProtKB  
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Hydropathy has been calculated using a sliding window of 15 residues and summing up scores from standard hydrophobicity tables.
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  • Blue: hydrophilic.
Data in lilac represent the genomic exon structure projected onto the UniProt sequence.
Data in blue originates from PDB
  • Secstruc: Secondary structure projected from representative PDB entries onto the UniProt sequence.
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The PDB to UniProt mapping is based on the data provided by the EBI SIFTS project. See also Velankar et al., Nucleic Acids Research 33, D262-265 (2005).
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