DNA gyrase subunit A - P9WG47 (GYRA_MYCTU)

 

Protein Feature View of PDB entries mapped to a UniProtKB sequence  

  • Number of PDB entries for P9WG47: 15
 
Function
A type II topoisomerase that negatively supercoils closed circular double-stranded (ds) DNA in an ATP-dependent manner to maintain chromosomes in an underwound state, while in the absence of ATP it relaxes supercoiled dsDNA (PubMed:15047530, PubMed:16377674, PubMed:16876125, PubMed:17015625, PubMed:18426901, PubMed:19060136, PubMed:22844097, PubMed:20805881). Also catalyzes the interconversion of other topological isomers of dsDNA rings, including catenanes (PubMed:16876125, PubMed:19060136, PubMed:22457352). Gyrase from M.tuberculosis has higher decatenation than supercoiling activity compared to E.coli; as M.tuberculosis only has 1 type II topoisomerase, gyrase has to fulfill the decatenation function of topoisomerase IV as well (PubMed:16876125, PubMed:22457352, PubMed:23869946). At comparable concentrations M.tuberculosis gyrase cannot introduce as many negative supercoils into DNA as the E.coli enzyme, and its ATPase activity is lower, perhaps because it does not couple DNA wrapping and ATP binding as well as E.coli (PubMed:22457352). UniProt
Catalytic Activity
ATP-dependent breakage, passage and rejoining of double-stranded DNA. UniProt
Pathway Maps
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Subunit Structure
Heterotetramer, composed of two GyrA and two GyrB chains. In the heterotetramer, GyrA contains the active site tyrosine that forms a transient covalent intermediate with DNA, while GyrB binds cofactors and catalyzes ATP hydrolysis (PubMed:15047530). UniProt
Domain
The N-terminal domain (residues 1-502, also called GA57BK) forms a dimer; when reconstituted with intact GyrB or the C-terminus of GyrB (residues 448-675) can catalyze quinolone-mediated DNA breaks (PubMed:20805881). The C-terminal domain (CTD, residues 514-838) contains 6 tandemly repeated subdomains known as blades, each of which is composed of a 4-stranded antiparallel beta-sheet (PubMed:22457352, PubMed:23869946). The blades form a circular-shaped beta-pinwheel fold arranged in a spiral around a screw axis, which binds DNA (PubMed:22457352, PubMed:23869946). Unlike in E.coli, isolated CTD both binds and wraps DNA and is able to introduce writhe into DNA, but the holoenzyme in M.tuberculosis is missing the GyrA acidic tail found in E.coli and thus does not couple DNA wrapping and ATP binding as well as E.coli (PubMed:22457352). There are 2 GyrA-boxes in the CTD; mutations in GyrA-box (residues 537-543, the canonical box) affect supercoiling but not decatenation, those in GyrA-box-1 (residues 743-749, conserved in some Actinobacteria) affect both, suggesting there is a novel DNA-binding pathway in M.tuberculosis compared to E.coli (PubMed:23869946). UniProt
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Data in green originates from UniProtKB  
Variation data (sourced from UniProt) shows non-genetic variation from the ExPASy   and dbSNP   websites.
Data in yellow originates from Pfam  , by interacting with the HMMER3 web site  
Data in purple originates from Phosphosite  .
Data in orange originates from the SCOP   (version 1.75) and SCOPe   (version 2.04) classifications.
Data in grey has been calculated using BioJava  . Protein disorder predictions are based on JRONN (Troshin, P. and Barton, G. J. unpublished), a Java implementation of RONN  
  • Red: potentially disorderd region
  • Blue: probably ordered region.
Hydropathy has been calculated using a sliding window of 15 residues and summing up scores from standard hydrophobicity tables.
  • Red: hydrophobic
  • Blue: hydrophilic.
Data in lilac represent the genomic exon structure projected onto the UniProt sequence.
Data in blue originates from PDB
  • Secstruc: Secondary structure projected from representative PDB entries onto the UniProt sequence.
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Validation Track

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Data in red indicates combined ranges of Homology Models from the SWISS-MODEL Repository  
The PDB to UniProt mapping is based on the data provided by the EBI SIFTS project. See also Velankar et al., Nucleic Acids Research 33, D262-265 (2005).
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