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Protein FULL name:

DNA polymerase III beta-subunit [Escherichia coli].

DnaN (Escherichia coli strain K-12 substr. MG1655) is product of expression of dnaN gene.

DnaN is involved in:

MMR in Escherichia coli strain K-12 substr. MG1655


FUNCTION: DNA polymerase III is a complex, multichain enzyme responsible for most of the replicative synthesis in bacteria. This DNA polymerase also exhibits 3' to 5' exonuclease activity. The beta chain is required for initiation of replication once it is clamped onto DNA, it slides freely (bidirectional and ATP- independent) along duplex DNA.

CATALYTIC ACTIVITY: Deoxynucleoside triphosphate + DNA(n) = diphosphate + DNA(n+1).

SUBUNIT: The DNA polymerase holoenzyme is a complex that contains 10 different types of subunits. These subunits are organized into 3 functionally essential subassemblies: the pol III core, the beta sliding clamp processivity factor and the clamp-loading complex. The pol III core (subunits alpha,epsilon and theta) contains the polymerase and the 3'-5' exonuclease proofreading activities. The polymerase is tethered to the template via the sliding clamp processivity factor. The clamp-loading complex assembles the beta processivity factor onto the primer template and plays a central role in the organization and communication at the replication fork. This complex contains delta, delta', psi and chi, and copies of either or both of two different dnaX proteins, gamma and tau. The composition of the holoenzyme is, therefore: (alpha,epsilon,theta)[2]-(gamma/tau)[3]-delta,delta', psi,chi- beta[4]. The beta chain is a homodimer when not associated with the other components.

INTERACTION: P06710:dnaX; NbExp=1; IntAct=EBI-542385, EBI-549140; P0A6F5:groL; NbExp=1; IntAct=EBI-542385, EBI-543750; P69931:hda; NbExp=1; IntAct=EBI-542385, EBI-545453; P28630:holA; NbExp=2; IntAct=EBI-542385, EBI-549153; P0AG07:rpe; NbExp=1; IntAct=EBI-542385, EBI-546020; P05845:tnsE (xeno); NbExp=2; IntAct=EBI-542385, EBI-2434514; P0A8E7:yajQ; NbExp=1; IntAct=EBI-542385, EBI-370752; P77395:ybbN; NbExp=1; IntAct=EBI-542385, EBI-545297; P0AFX0:yhbH; NbExp=1; IntAct=EBI-542385, EBI-561113; P0AC53:zwf; NbExp=1; IntAct=EBI-542385, EBI-555656;


This protein can be a part of a given complexes:
NCBI GenPept GI number(s): 145761
Species: Escherichia coli

Links to other databases:

Database ID Link
Uniprot P0A988 P0A988
PFAM: - P0A988 (Link - using uniprot id)
InterPro: - P0A988 (Link - using uniprot id)
CATH: - -
SCOP: - -
PDB: - -

Protein sequence:


Title Authors Journal
Structural analysis of the dnaA and dnaN genes of Escherichia coli. Ohmori H, Kimura M, Nagata T, Sakakibara Y Gene May 1, 1984
Molecular analysis of the recF gene of Escherichia coli. Blanar MA, Sandler SJ, Armengod ME, Ream LW, Clark AJ Proc Natl Acad Sci U S A Aug. 1, 1984
DNA sequence and transcription of the region upstream of the E. coli gyrB gene. Adachi T, Mizuuchi K, Menzel R, Gellert M Nucleic Acids Res Aug. 24, 1984
Overlapping arrangement of the recF and dnaN operons of Escherichia coli; positive and negative control sequences. Armengod ME, Lambies E Gene Jan. 1, 1986
Transcriptional organization of the dnaN and recF genes of Escherichia coli K-12. Armengod ME, Garcia-Sogo M, Lambies E J Biol Chem Aug. 25, 1988
Accessory protein function in the DNA polymerase III holoenzyme from E. coli. O'Donnell M Bioessays Jan. 1, 1992
Three-dimensional structure of the beta subunit of E. coli DNA polymerase III holoenzyme: a sliding DNA clamp. Kong XP, Onrust R, O'Donnell M, Kuriyan J Cell May 1, 1992
DNA sequence and analysis of 136 kilobases of the Escherichia coli genome: organizational symmetry around the origin of replication. Burland V, Plunkett G 3rd, Daniels DL, Blattner FR Genomics June 1, 1993
The complete genome sequence of Escherichia coli K-12. Blattner FR, Plunkett G 3rd, Bloch CA, Perna NT, Burland V, Riley M, Collado-Vides J, Glasner JD, Rode CK, Mayhew GF, Gregor J, Davis NW, Kirkpatrick HA, Goeden MA, Rose DJ, Mau B, Shao Y Science Sept. 5, 1997
Flexibility revealed by the 1.85 A crystal structure of the beta sliding-clamp subunit of Escherichia coli DNA polymerase III. Oakley AJ, Prosselkov P, Wijffels G, Beck JL, Wilce MC, Dixon NE Acta Crystallogr D Biol Crystallogr July 1, 2003
Structural basis for recruitment of translesion DNA polymerase Pol IV/DinB to the beta-clamp. Bunting KA, Roe SM, Pearl LH EMBO J Nov. 3, 2003
Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110. Hayashi K, Morooka N, Yamamoto Y, Fujita K, Isono K, Choi S, Ohtsubo E, Baba T, Wanner BL, Mori H, Horiuchi T Mol Syst Biol Jan. 1, 2006

Last modification of this entry: Oct. 12, 2010.

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