6p4f

Crystal structure of the XPB-Bax1-forked DNA ternary complex

spinqualitylabelsall models 6p4f, resolution 3.55Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6p4f is a 8 chain structure with sequence from Sulfurisphaera tokodaii str. 7 and Synthetic construct. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.55Å Ligands: CL, MG, PO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q970I2_SULTO Publication Abstract from PubMed Nucleotide excision repair (NER) removes various DNA lesions caused by UV light and chemical carcinogens. The DNA helicase XPB plays a key role in DNA opening and coordinating damage incision by nucleases during NER, but the underlying mechanisms remain unclear. Here, we report crystal structures of XPB from Sulfurisphaera tokodaii (St) bound to the nuclease Bax1 and their complex with a bubble DNA having one arm unwound in the crystal. StXPB and Bax1 together spirally encircle 10 base pairs of duplex DNA at the double-/single-stranded (ds-ss) junction. Furthermore, StXPB has its ThM motif intruding between the two DNA strands and gripping the 3'-overhang while Bax1 interacts with the 5'-overhang. This ternary complex likely reflects the state of repair bubble extension by the XPB and nuclease machine. ATP binding and hydrolysis by StXPB could lead to a spiral translocation along dsDNA and DNA strand separation by the ThM motif, revealing an unconventional DNA unwinding mechanism. Interestingly, the DNA is kept away from the nuclease domain of Bax1, potentially preventing DNA incision by Bax1 during repair bubble extension. Structural basis of the XPB helicase-Bax1 nuclease complex interacting with the repair bubble DNA.,He F, DuPrez K, Hilario E, Chen Z, Fan L Nucleic Acids Res. 2020 Nov 18;48(20):11695-11705. doi: 10.1093/nar/gkaa801. PMID:32986831 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Endonuclease 3D structures

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