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DNA polymerase alpha catalytic subunit - P09884 (DPOLA_HUMAN)

 

Protein Feature View of PDB entries mapped to a UniProtKB sequence  

Number of PDB entries for P09884: 3
 
Function
Plays an essential role in the initiation of DNA replication. During the S phase of the cell cycle, the DNA polymerase alpha complex (composed of a catalytic subunit POLA1/p180, a regulatory subunit POLA2/p70 and two primase subunits PRIM1/p49 and PRIM2/p58) is recruited to DNA at the replicative forks via direct interactions with MCM10 and WDHD1. The primase subunit of the polymerase alpha complex initiates DNA synthesis by oligomerising short RNA primers on both leading and lagging strands. These primers are initially extended by the polymerase alpha catalytic subunit and subsequently transferred to polymerase delta and polymerase epsilon for processive synthesis on the lagging and leading strand, respectively. The reason this transfer occurs is because the polymerase alpha has limited processivity and lacks intrinsic 3' exonuclease activity for proofreading error, and therefore is not well suited for replicating long complexes. (data source: UniProt  )
Catalytic Activity

Deoxynucleoside triphosphate + DNA(n) = diphosphate + DNA(n+1).

(data source: UniProt  )
Subunit structure
The DNA polymerase alpha complex is composed of four subunits: the catalytic subunit POLA1, the regulatory subunit POLA2, and the small and the large primase subunits PRIM1 and PRIM2 respectively. Interacts with PARP1; this interaction functions as part of the control of replication fork progression. Interacts with MCM10 and WDHD1; these interactions recruit the polymerase alpha complex to the pre-replicative complex bound to DNA. Interacts with RPA1; this interaction stabilizes the replicative complex and reduces the misincorporation rate of DNA polymerase alpha by acting as a fidelity clamp. Interacts with SV40 Large T antigen; this interaction allows viral DNA replication. Interacts with herpes simplex virus 1 (HHV-1) replication origin-binding protein UL9. (data source: UniProt  )
Domain
The CysB motif binds 1 4Fe-4S cluster and is required for the formation of polymerase complexes. (data source: UniProt  )
UniProtKB:
Species: 
Gene names: Gene View for POLA1 POLA
Length:
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Data origin/color codes
The vertical color bar on the left side indicates data provenance.
Data in green originates from UniProtKB  
Data in yellow originates from Pfam  , by interacting with the HMMER3 web site  
Data in orange originates from the SCOP   (version 1.75) and SCOPe   (version 2.04) classifications.
Data in grey has been calculated using BioJava  . Protein disorder predictions are based on JRONN (Troshin, P. and Barton, G. J. unpublished), a Java implementation of RONN  
  • Red: potentially disorderd region
  • Blue: probably ordered region.
Hydropathy has been calculated using a sliding window of 15 residues and summing up scores from standard hydrophobicity tables.
  • Red: hydrophobic
  • 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.
Data in red indicates combined ranges of Homology Models from SBKB   and the Protein Model Portal  

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).