4r1f

Re-refined Human DNA topoisomerase IIa (ATPase and transducer domains) in complex with ADP and SO4

spinqualitylabelsall models 4r1f, resolution 2.51Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4r1f is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.51Å Ligands: ADP, GOL, MG, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function TOP2A_HUMAN Control of topological states of DNA by transient breakage and subsequent rejoining of DNA strands. Topoisomerase II makes double-strand breaks. Essential during mitosis and meiosis for proper segregation of daughter chromosomes. Publication Abstract from PubMed Type II DNA topoisomerases are essential enzymes that catalyze topological rearrangement of double-stranded DNA using the free energy generated by ATP hydrolysis. Bacterial DNA gyrase is a prototype of this family and is composed of two subunits (GyrA, GyrB) that form a GyrA2GyrB2 heterotetramer. The N-terminal 43-kDa fragment of GyrB (GyrB43) from E. coli comprising the ATPase and the transducer domains has been studied extensively. The dimeric fragment is competent for ATP hydrolysis and its structure in complex with the substrate analog AMPPNP is known. Here, we have determined the remaining conformational states of the enzyme along the ATP hydrolysis reaction path by solving crystal structures of GyrB43 in complex with ADPBeF3, ADPPi, and ADP. Upon hydrolysis, the enzyme undergoes an obligatory 12 degrees domain rearrangement to accommodate the 1.5 A increase in distance between the gamma- and beta-phosphate of the nucleotide within the sealed binding site at the domain interface. Conserved residues from the QTK loop of the transducer domain (also part of the domain interface) couple the small structural change within the binding site with the rigid body motion. The domain reorientation is reflected in a significant 7 A increase in the separation of the two transducer domains of the dimer that would embrace one of the DNA segments in full-length gyrase. The observed conformational change is likely to be relevant for the allosteric coordination of ATP hydrolysis with DNA binding, cleavage/re-ligation and/or strand passage. Structure of the N-Terminal Gyrase B Fragment in Complex with ADPPi Reveals Rigid-Body Motion Induced by ATP Hydrolysis.,Stanger FV, Dehio C, Schirmer T PLoS One. 2014 Sep 9;9(9):e107289. doi: 10.1371/journal.pone.0107289. eCollection, 2014. PMID:25202966 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Topoisomerase 3D structures

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