DNA Polymerase III Holoenzyme - Components

Components

Bacterial DNA polymerase III alpha subunit
Identifiers
Symbol DNA_pol3_alpha
Pfam PF07733
InterPro IPR011708
Available protein structures:
Pfam structures
PDB RCSB PDB; PDBe
PDBsum structure summary
DNA polymerase III, delta subunit
atpgs bound e. coli clamp loader complex
Identifiers
Symbol DNA_pol3_delta
Pfam PF06144
Pfam clan CL0023
InterPro IPR010372
SCOP 1jql
SUPERFAMILY 1jql
Available protein structures:
Pfam structures
PDB RCSB PDB; PDBe
PDBsum structure summary
DNA polymerase III, delta subunit, C terminal
adp bound e. coli clamp loader complex
Identifiers
Symbol DNApol3-delta_C
Pfam PF09115
InterPro IPR015199
SCOP 1a5t
SUPERFAMILY 1a5t
Available protein structures:
Pfam structures
PDB RCSB PDB; PDBe
PDBsum structure summary
DNA polymerase III subunits tau domain IV DnaB-binding
Identifiers
Symbol DNA_pol3_tau_4
Pfam PF12168
InterPro IPR022001
Available protein structures:
Pfam structures
PDB RCSB PDB; PDBe
PDBsum structure summary
DNA polymerase III tau subunit V interacting with alpha
Identifiers
Symbol DNA_pol3_tau_5
Pfam PF12170
InterPro IPR021029
Available protein structures:
Pfam structures
PDB RCSB PDB; PDBe
PDBsum structure summary
DNA polymerase III, theta subunit
structure of the e. coli pol iii epsilon-hot proofreading complex
Identifiers
Symbol DNA_pol3_theta
Pfam PF06440
InterPro IPR009052
SCOP 1du2
SUPERFAMILY 1du2
Available protein structures:
Pfam structures
PDB RCSB PDB; PDBe
PDBsum structure summary
DNA polymerase III chi subunit, HolC
crystal structure of chi and psi subunit heterodimer from dna pol iii
Identifiers
Symbol DNA_pol3_chi
Pfam PF04364
InterPro IPR007459
SCOP 1em8
SUPERFAMILY 1em8
Available protein structures:
Pfam structures
PDB RCSB PDB; PDBe
PDBsum structure summary

The replisome is composed of the following:

  • 2 DNA Pol III enzymes, each comprising α, ε and θ subunits.
    • the α subunit has the polymerase activity.
    • the ε subunit has 3'-5' exonuclease activity.
    • the θ subunit stimulates the ε subunit's proofreading.
  • 2 β units which act as sliding DNA clamps, they keep the polymerase bound to the DNA.
  • 2 τ units which acts to dimerize two of the core enzymes (α, ε, and θ subunits).
  • 1 γ unit which acts as a clamp loader for the lagging strand Okazaki fragments, helping the two β subunits to form a unit and bind to DNA. The γ unit is made up of 5 γ subunits which include 3 γ subunits, 1 δ subunit, and 1 δ' subunit. The δ is involved in copying of the lagging strand.
  • Χ and Ψ which form a 1:1 complex and bind to γ or τ.

Read more about this topic:  DNA Polymerase III Holoenzyme

Famous quotes containing the word components:

    “Hence, a generative grammar must be a system of rules that can iterate to generate an indefinitely large number of structures. This system of rules can be analyzed into the three major components of a generative grammar: the syntactic, phonological, and semantic components.”
    —Noam Chomsky (b. 1928)