Summary: Topoisomerase VI B subunit, transducer
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Topoisomerase VI B subunit, transducer Provide feedback
Members of this family adopt a structure consisting of a four-stranded beta-sheet backed by three alpha-helices, the last of which is over 50 amino acids long and extends from the body of the protein by several turns. This domain has been proposed to mediate intersubunit communication by structurally transducing signals from the ATP binding and hydrolysis domains to the DNA binding and cleavage domains of the gyrase holoenzyme .
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This tab holds annotation information from the InterPro database.
InterPro entry IPR015320
DNA topoisomerases regulate the number of topological links between two DNA strands (i.e. change the number of superhelical turns) by catalysing transient single- or double-strand breaks, crossing the strands through one another, then resealing the breaks [PUBMED:7770916]. These enzymes have several functions: to remove DNA supercoils during transcription and DNA replication; for strand breakage during recombination; for chromosome condensation; and to disentangle intertwined DNA during mitosis [PUBMED:12042765, PUBMED:11395412]. DNA topoisomerases are divided into two classes: type I enzymes (EC; topoisomerases I, III and V) break single-strand DNA, and type II enzymes (EC; topoisomerases II, IV and VI) break double-strand DNA [PUBMED:12596227].
Type II topoisomerases are ATP-dependent enzymes, and can be subdivided according to their structure and reaction mechanisms: type IIA (topoisomerase II or gyrase, and topoisomerase IV) and type IIB (topoisomerase VI). These enzymes are responsible for relaxing supercoiled DNA as well as for introducing both negative and positive supercoils [PUBMED:7980433].
This entry represents subunit B of topoisomerase VI, an ATP-dependent type IIB enzyme. Members of this family adopt a structure consisting of a four-stranded beta-sheet backed by three alpha-helices, the last of which is over 50 amino acids long and extends from the body of the protein by several turns. This domain has been proposed to mediate intersubunit communication by structurally transducing signals from the ATP binding and hydrolysis domains to the DNA binding and cleavage domains of the gyrase holoenzyme [PUBMED:12505993].
More information about this protein can be found at Protein of the Month: DNA Topoisomerase [PUBMED:].
|Cellular component||chromosome (GO:0005694)|
|Molecular function||DNA binding (GO:0003677)|
|DNA topoisomerase (ATP-hydrolyzing) activity (GO:0003918)|
|Biological process||DNA topological change (GO:0006265)|
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|Number in seed:||36|
|Number in full:||213|
|Average length of the domain:||155.40 aa|
|Average identity of full alignment:||40 %|
|Average coverage of the sequence by the domain:||26.23 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||6|
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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Topo-VIb_trans domain has been found. There are 20 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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