4ddq

Structural plasticity of the Bacillus subtilis GyrA homodimer

spinqualitylabelsall models 4ddq, resolution 3.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4ddq is a 6 chain structure with sequence from Bacillus subtilis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: K, TRS Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [GYRA_BACSU] DNA gyrase negatively supercoils closed circular double-stranded DNA in an ATP-dependent manner and also catalyzes the interconversion of other topological isomers of double-stranded DNA rings, including catenanes and knotted rings (By similarity). Publication Abstract from PubMed Type II DNA topoisomerases alter the supercoiling state of DNA in an ATP-dependent fashion that requires large conformational changes. The directionality of DNA strand transfer is controlled by three transient protein interfaces, termed the N-gate, DNA-gate, and C-gate. Bacterial gyrase is a type II DNA topoisomerase of A2B2 composition. The N-gate is formed by the two GyrB subunits and the GyrA subunits form the DNA- and C-gates. In structures of type II topoisomerase fragments, the DNA- and C-gates delimit a cavity for DNA and can be open or closed. However, the conformational space accessible has not yet been mapped. Here, we describe the crystal structure of the Bacillus subtilis DNA gyrase A subunit lacking the C-terminal DNA-wrapping domains. Five dimeric states of the GyrA N-terminal domain are observed, with their DNA- and C-gates either closed, or open to different extents. All of these conformations can in principle accommodate double-stranded DNA in the central cavity but only one conformation has its DNA-gate open wide enough for DNA to enter. The structure thus reflects the lower limit of DNA-gate opening that must occur during gyrase catalysis. The DNA-gate is formed by two flat surfaces, with few interactions. In contrast, the C-gate exhibits a highly undulated surface and forms a large number of interactions. None of the dimers in the crystal structures display an open C-gate that would allow DNA passage, in agreement with a transient opening of this gate during the catalytic cycle of DNA supercoiling. Mapping the Spectrum of Conformational States of the DNA- and C-Gates in Bacillus subtilis Gyrase.,Rudolph MG, Klostermeier D J Mol Biol. 2013 Apr 16. pii: S0022-2836(13)00241-6. doi:, 10.1016/j.jmb.2013.04.010. PMID:23602808 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Gyrase 3D Structures

Proteopedia Page Contributors and Editors (what is this?)

OCA