SUPERFAMILY 1.75 HMM library and genome assignments server

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DNA polymerase III theta subunit-like superfamily

SCOP classification
Root:   SCOP hierarchy in SUPERFAMILY [ 0] (11)
Class:   All alpha proteins [ 46456] (284)
Fold:   DNA polymerase III theta subunit-like [ 116730]
Superfamily:   DNA polymerase III theta subunit-like [ 46575]
Families:   DNA polymerase III theta subunit-like [ 46576] (2)

Superfamily statistics
Genomes (218) Uniprot 2018_03 genome PDB chains (SCOP 1.75)
Domains 373 1,897 2
Proteins 373 1,897 2

Functional annotation
General category Information
Detailed category DNA replication/repair

Function annotation of SCOP domain superfamilies

InterPro annotation
Cross references IPR009052 SSF46575 Protein matches

This entry represents the theta subunit of DNA polymerase III from bacteria, whose core structure consists of an irregular array of three helices [PubMed10794414].

DNA polymerase III (Pol III) is the primary enzyme responsible for replication of Escherichia coli chromosomal DNA. The holoenzyme consists of 17 proteins and contains two core polymerases. The Pol III catalytic core has three tightly associated subunits: alpha, epsilon and theta. The alpha subunit is responsible for the DNA polymerase activity, while the epsilon subunit is the 3'-5' proofreading exonuclease. The epsilon subunit binds to both the alpha and theta subunits in the linear order alpha-epsilon-theta. The theta subunit is the smallest, and may act to enhance the proofreading activity of epsilon, especially under extreme conditions [PubMed16753031].

This entry also includes a homologue of polymerase III theta called HOT (homolog of theta) from Bacteriophage P1. HOT contains three alpha-helices, as reported for theta, but the folding topology of the two is different, which could account for the suggested greater heat stability of HOT as compared to theta [PubMed15576035].

InterPro database

PDBeMotif information about ligands, sequence and structure motifs
Cross references PDB entries
Ligand binding statistics
Nucleic-acid binding statistics
Occurrence of secondary structure elements
Occurrence of small 3D structural motifs

PDBeMotif resource

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Internal database links

Browse genome assignments for this superfamily. The SUPERFAMILY hidden Markov model library has been used to carry out SCOP domain assignments to all genomes at the superfamily level.

Alignments of sequences to 2 models in this superfamily are available by clicking on the 'Alignments' icon above. PDB sequences less than 40% identical are shown by default, but any other sequence(s) may be aligned. Select PDB sequences, genome sequences, or paste in or upload your own sequences.

Browse and view proteins in genomes which have different domain combinations including a DNA polymerase III theta subunit-like domain.

Examine the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.

Explore domain occurrence network where nodes represent genomes and edges are domain architectures (shared between genomes) containing the superfamily of interest.

There are 2 hidden Markov models representing the DNA polymerase III theta subunit-like superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be inspected.

Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation · Internal database links ]