PDBsum entry 4e2i

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protein metals Protein-protein interface(s) links
Hydrolase/DNA binding protein PDB id
Jmol PyMol
Protein chains
(+ 6 more) 362 a.a.
(+ 5 more) 78 a.a.
_ZN ×12
PDB id:
Name: Hydrolase/DNA binding protein
Title: The complex structure of the sv40 helicase large t antigen a subunit of DNA polymerase alpha-primase
Structure: Large t antigen. Chain: a, b, c, d, e, f, g, h, i, j, k, l. Fragment: unp residues 266-627. Engineered: yes. DNA polymerase alpha subunit b. Chain: 2, 3, 6, u, w, 5, 7, 9, 1, 4, 8. Fragment: unp residues 1-78. Synonym: DNA polymerase alpha 70 kda subunit. Engineered: yes
Source: Simian virus 40. Sv40. Organism_taxid: 10633. Expressed in: escherichia coli. Expression_system_taxid: 562. Homo sapiens. Human. Organism_taxid: 9606. Gene: pola2.
5.00Å     R-factor:   0.305     R-free:   0.314
Authors: B.Zhou,D.R.Arnett,X.Yu,A.Brewster,G.A.Sowd,C.L.Xie,S.Vila,D. E.Fanning,X.S.Chen
Key ref: B.Zhou et al. (2012). Structural basis for the interaction of a hexameric replicative helicase with the regulatory subunit of human DNA polymerase α-primase. J Biol Chem, 287, 26854-26866. PubMed id: 22700977 DOI: 10.1074/jbc.M112.363655
08-Mar-12     Release date:   13-Jun-12    
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Protein chains
Pfam   ArchSchema ?
P03070  (LT_SV40) -  Large T antigen
708 a.a.
362 a.a.*
Protein chains
Pfam   ArchSchema ?
Q14181  (DPOA2_HUMAN) -  DNA polymerase alpha subunit B
598 a.a.
78 a.a.
Key:    PfamA domain  Secondary structure
* PDB and UniProt seqs differ at 2 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     DNA replication   1 term 
  Biochemical function     DNA binding     2 terms  


DOI no: 10.1074/jbc.M112.363655 J Biol Chem 287:26854-26866 (2012)
PubMed id: 22700977  
Structural basis for the interaction of a hexameric replicative helicase with the regulatory subunit of human DNA polymerase α-primase.
B.Zhou, D.R.Arnett, X.Yu, A.Brewster, G.A.Sowd, C.L.Xie, S.Vila, D.Gai, E.Fanning, X.S.Chen.
DNA polymerase α-primase (Pol-prim) plays an essential role in eukaryotic DNA replication, initiating synthesis of the leading strand and of each Okazaki fragment on the lagging strand. Pol-prim is composed of a primase heterodimer that synthesizes an RNA primer, a DNA polymerase subunit that extends the primer, and a regulatory B-subunit (p68) without apparent enzymatic activity. Pol-prim is thought to interact with eukaryotic replicative helicases, forming a dynamic multiprotein assembly that displays primosome activity. At least three subunits of Pol-prim interact physically with the hexameric replicative helicase SV40 large T antigen, constituting a simple primosome that is active in vitro. However, structural understanding of these interactions and their role in viral chromatin replication in vivo remains incomplete. Here, we report the detailed large T antigen-p68 interface, as revealed in a co-crystal structure and validated by site-directed mutagenesis, and we demonstrate its functional importance in activating the SV40 primosome in cell-free reactions with purified Pol-prim, as well as in monkey cells in vivo.