Summary

DNA gyrase C-terminal domain, beta-propeller

This repeat is found as 6 tandem copies at the C-termini of GyrA and ParC DNA gyrases. It is predicted to form 4 beta strands and to probably form a beta-propeller structure [1]. This region has been shown to bind DNA non-specifically and may stabilise the DNA-topoisomerase complex [2].

Literature references

Qi Y, Pei J, Grishin NV; , Proteins 2002;47:258-264.: C-terminal domain of gyrase A is predicted to have a beta-propeller structure. PUBMED:11948780
Reece RJ, Maxwell A; , Crit Rev Biochem Mol Biol 1991;26:335-375.: DNA gyrase: structure and function. PUBMED:1657531

InterPro entry IPR006691

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.

This entry represents the beta-pinwheel repeat found at the C-terminal end of subunit A of topoisomerase IV (ParC) and subunit A of DNA gyrase (GyrA). DNA gyrase is the topoisomerase II found primarily in bacteria and archaea that consists of two polypeptide subunits, gyrA and gyrB, which form a heterotetramer: (BA)2. This is distinct from the topoisomerase II found in most eukaryotes, which consists of a single polypeptide, with the N- and C-terminal regions corresponding to gyrB and gyrA, respectively, and which is not represented in this entry.

The ability of DNA gyrase to introduce negative supercoils into DNA is mediated in part by the C-terminal domain of subunit A, which forms a beta-pinwheel fold that is similar to a beta-propeller but with a different blade topology, and which forms a superhelical spiral domain PUBMED:15123801, PUBMED:15897198. This beta-pinwheel is capable of bending DNA by over 180 degrees over a 40 bp region, possibly by wrapping the DNA around the GyrA C-terminal beta-pinwheel domain.

In topoisomerase IV, although the C-terminal domain forms a similar superhelical spiral to that of DNA gyrase A, it assembles as a broken form of a beta-pinwheel as distinct from that of gyrA, due to the absence of a DNA gyrase-specific GyrA box motif PUBMED:15466871. This difference may account for parC being less efficient than gyrA in mediating DNA-bending, leading to their divergence in terms of activity, where topoisomerase IV acts to relax positive supercoils, and DNA gyrase acts to introduce negative supercoils PUBMED:16023670.

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 activity (GO:0003916)
Biological process	DNA topological change (GO:0006265)

External database links

PANDIT:	PF03989
SCOP:	1suu
SYSTERS:	DNA_gyraseA_C

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...

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Alignment:	Seed (362) Full (13560) NCBI (24325) Metagenomics (14911)
Viewer:

Formatting options

Alignment:	Seed (362) Full (13560)
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 (362) Full (13560) NCBI (24325) Metagenomics (14911)
Full length sequences	Full-sequences (13560)

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:

Yeats C

Previous IDs:

none

Type:

Repeat

Author:

Yeats C

Number in seed:

362

Number in full:

13560

Average length of the domain:

49.60 aa

Average identity of full alignment:

21 %

Average coverage of the sequence by the domain:

5.97 %

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	20.4	4.0
Trusted cut-off	20.4	4.0
Noise cut-off	20.3	3.9

Model length:

50

Family (HMM) version:

6

Download:

download the raw HMM for this family

Species distribution

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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:

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highlight species that are represented in the seed alignment
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Interactions

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DNA_gyraseA_C

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_gyraseA_C domain has been found.

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Family: DNA_gyraseA_C (PF03989)

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