Summary

DNA gyrase B

This family represents the second domain of DNA gyrase B which has a ribosomal S5 domain 2-like fold. This family is structurally related to PF01119.

Literature references

Wigley DB, Davies GJ, Dodson EJ, Maxwell A, Dodson G; , Nature 1991;351:624-629.: Crystal structure of an N-terminal fragment of the DNA gyrase B protein. PUBMED:1646964
Brino L, Urzhumtsev A, Mousli M, Bronner C, Mitschler A, Oudet P, Moras D , J Biol Chem 2000;275:9468-9475.: Dimerization of Escherichia coli DNA-gyrase B provides a structural mechanism for activating the ATPase catalytic center. PUBMED:10734094
Brino L, Bronner C, Oudet P, Mousli M , Biochimie 1999;81:973-980.: Isoleucine 10 is essential for DNA gyrase B function in Escherichia coli. PUBMED:10575351
Tanaka T, Saha SK, Tomomori C, Ishima R, Liu D, Tong KI, Park H, Dutta R, Qin L, Swindells MB, Yamazaki T, Ono AM, Kainosho M, Inouye M, Ikura M , Nature 1998;396:88-92.: NMR structure of the histidine kinase domain of the E. coli osmosensor EnvZ. PUBMED:9817206
Smith CV, Maxwell A , Biochemistry 1998;37:9658-9667.: Identification of a residue involved in transition-state stabilization in the ATPase reaction of DNA gyrase. PUBMED:9657678
Prodromou C, Roe SM, O'Brien R, Ladbury JE, Piper PW, Pearl LH , Cell 1997;90:65-75.: Identification and structural characterization of the ATP/ADP-binding site in the Hsp90 molecular chaperone. PUBMED:9230303

InterPro entry IPR013506

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. 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 (; topoisomerases I, III and V) break single-strand DNA, and type II enzymes (; 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.

Type IIA topoisomerases together manage chromosome integrity and topology in cells. Topoisomerase II (called gyrase in bacteria) primarily introduces negative supercoils into DNA. In bacteria, topoisomerase II consists of two polypeptide subunits, gyrA and gyrB, which form a heterotetramer: (BA)2. In most eukaryotes, topoisomerase II consists of a single polypeptide, where the N- and C-terminal regions correspond to gyrB and gyrA, respectively; this topoisomerase II forms a homodimer that is equivalent to the bacterial heterotetramer. There are four functional domains in topoisomerase II: domain 1 (N-terminal of gyrB) is an ATPase, domain 2 (C-terminal of gyrB) is responsible for subunit interactions, domain 3 (N-terminal of gyrA) is responsible for the breaking-rejoining function through its capacity to form protein-DNA bridges, and domain 4 (C-terminal of gyrA) is able to non-specifically bind DNA PUBMED:8982450.

Topoisomerase IV primarily decatenates DNA and relaxes positive supercoils, which is important in bacteria, where the circular chromosome becomes catenated, or linked, during replication PUBMED:16023670. Topoisomerase IV consists of two polypeptide subunits, parE and parC, where parC is homologous to gyrA and parE is homologous to gyrB.

This entry represents the second domain found in subunit B (gyrB and parE) of bacterial gyrase and topoisomerase IV, and the equivalent N-terminal region in eukaryotic topoisomerase II composed of a single polypeptide.

More information about this protein can be found at Protein of the Month: DNA Topoisomerase PUBMED:.

Gene Ontology

Cellular component	chromosome (GO:0005694)
Molecular function	DNA binding (GO:0003677)
	ATP binding (GO:0005524)
	DNA topoisomerase (ATP-hydrolyzing) activity (GO:0003918)
Biological process	DNA topological change (GO:0006265)

External database links

PANDIT:	PF00204
PRINTS:	PR00418
PROSITE:	PDOC00160
SCOP:	1bgw
SYSTERS:	DNA_gyraseB

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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Alignments

There are various ways to view or download the sequence alignments that we store. You can use a sequence viewer to look at either the seed or full alignment for the family, or you can look at a plain text version of the sequence in a variety of different formats. More...

View options

Alignment:	Seed (99) Full (8504) NCBI (14443) Metagenomics (4292)
Viewer:

Formatting options

Alignment:	Seed (99) Full (8504)
Format:
Order:	Tree Alphabetical
Sequence:	Inserts lower case All upper case
Gaps:
Download/view:	Download View

Download options

Very large alignments can often cause problems for the formatting tool above. If you find that downloading or viewing a large alignment is problematic, you can also download a gzip-compressed, Stockholm-format file containing the seed or full alignment for this family.

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

The main seed and full alignments are generated using sequences from the UniProt sequence database. However, we also generate alignments using sequences from the NCBI sequence database and the "metaseq" metagenomics dataset.

You can view alignments from these two additional datasets using the form above, or you can download alignments of NCBI or metagenomics sequences, as gzip-compressed files.

Pfam alignments:	Seed (99) Full (8504) NCBI (14443) Metagenomics (4292)
Full length sequences	Full-sequences (8504)

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER2.

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...

Trees

This page displays the phylogenetic tree for this family. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed or full alignments.

Note: You can also download the data files for the seed, full, NCBI or metagenomics trees.

Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation

Seed source:

SCOP

Previous IDs:

DNA_topoisoII;

Type:

Domain

Author:

Finn RD, Griffiths-Jones SR

Number in seed:

99

Number in full:

8504

Average length of the domain:

161.40 aa

Average identity of full alignment:

44 %

Average coverage of the sequence by the domain:

32.75 %

HMM information

HMM build commands:

build method: hmmbuild -o /dev/null HMM SEED

search method: hmmsearch -Z 9421015 -E 1000 HMM pfamseq

Model details:

Parameter	Sequence	Domain
Gathering cut-off	20.7	20.7
Trusted cut-off	21.3	20.7
Noise cut-off	19.4	20.6

Model length:

173

Family (HMM) version:

18

Download:

download the raw HMM for this family

Species distribution

Tree controls

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The tree shows the occurrence of this domain across different species. More...

Species trees

We show the species tree in one of two ways. For smaller trees we try to show an interactive representation, which allows you to select specific nodes in the tree and view them as an alignment or as a set of Pfam domain graphics.

Unfortunately we have found that there are problems viewing the interactive tree when the it becomes larger than a certain limit. Furthermore, we have found that Internet Explorer can become unresponsive when viewing some trees, regardless of their size. We therefore show a text representation of the species tree when the size is above a certain limit or if you are using Internet Explorer to view the site.

If you are using IE you can still load the interactive tree by clicking the "Generate interactive tree" button, but please be aware of the potential problems that the interactive species tree can cause.

Interactive tree

For all of the domain matches in a full alignment, we count the number that are found on all sequences in the alignment. This total is shown in the purple box.

We also count the number of unique sequences on which each domain is found, which is shown in green. Note that a domain may appear multiple times on the same sequence, leading to the difference between these two numbers.

Finally, we group sequences from the same organism according to the NCBI code that is assigned by UniProt, allowing us to count the number of distinct sequences on which the domain is found. This value is shown in the pink boxes.

We use the NCBI species tree to group organisms according to their taxonomy and this forms the structure of the displayed tree. Note that in some cases the trees are too large (have too many nodes) to allow us to build an interactive tree, but in most cases you can still view the tree in a plain text, non-interactive representation. Those species which are represented in the seed alignment for this domain are highlighted.

You can use the tree controls to manipulate how the interactive tree is displayed:

show/hide the summary boxes
highlight species that are represented in the seed alignment
expand/collapse the tree or expand it to a given depth
select a sub-tree or a set of species within the tree and view them graphically or as an alignment
save a plain text representation of the tree

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Interactions

There are 2 interactions for this family. More...

HATPase_c DNA_gyraseB

Structures

For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the MSD 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 DNA_gyraseB domain has been found.

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Family: DNA_gyraseB (PF00204)

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