4i3h

A three-gate structure of topoisomerase IV from Streptococcus pneumoniae

spinqualitylabelsall models 4i3h, resolution 3.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4i3h is a 6 chain structure with sequence from Streptococcus pneumoniae TIGR4. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.7Å Ligands: MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function PARC_STRPN Topoisomerase IV is essential for chromosome segregation. It relaxes supercoiled DNA. Performs the decatenation events required during the replication of a circular DNA molecule. PARE_STRPN Topoisomerase IV is essential for chromosome segregation. It relaxes supercoiled DNA. Performs the decatenation events required during the replication of a circular DNA molecule. Publication Abstract from PubMed Type II topoisomerases regulate DNA supercoiling and chromosome segregation. They act as ATP-operated clamps that capture a DNA duplex and pass it through a transient DNA break in a second DNA segment via the sequential opening and closure of ATPase-, G-DNA- and C-gates. Here, we present the first 'open clamp' structures of a 3-gate topoisomerase II-DNA complex, the seminal complex engaged in DNA recognition and capture. A high-resolution structure was solved for a (full-length ParE-ParC55)2 dimer of Streptococcus pneumoniae topoisomerase IV bound to two DNA molecules: a closed DNA gate in a B-A-B form double-helical conformation and a second B-form duplex associated with closed C-gate helices at a novel site neighbouring the catalytically important beta-pinwheel DNA-binding domain. The protein N gate is present in an 'arms-wide-open' state with the undimerized N-terminal ParE ATPase domains connected to TOPRIM domains via a flexible joint and folded back allowing ready access both for gate and transported DNA segments and cleavage-stabilizing antibacterial drugs. The structure shows the molecular conformations of all three gates at 3.7 A, the highest resolution achieved for the full complex to date, and illuminates the mechanism of DNA capture and transport by a type II topoisomerase. Structure of an 'open' clamp type II topoisomerase-DNA complex provides a mechanism for DNA capture and transport.,Laponogov I, Veselkov DA, Crevel IM, Pan XS, Fisher LM, Sanderson MR Nucleic Acids Res. 2013 Aug 21. PMID:23965305 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Topoisomerase 3D structures

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