8bw5

X-ray structure of the complex between human alpha thrombin and the duplex/quadruplex aptamer M08s-1_41mer

spinqualitylabelsall models 8bw5, resolution 2.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 8bw5 is a 3 chain structure with sequence from Homo sapiens 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 2.8Å Ligands: 0G6, BMA, GAL, MAN, NA, NAG, SIA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Ligand/protein molecular recognition involves a dynamic process, whereby both partners require a degree of structural plasticity to regulate the binding/unbinding event. Here, we present the characterization of the interaction between a highly dynamic G-rich oligonucleotide, M08s-1, and its target protein, human alpha-thrombin. M08s-1 is the most active anticoagulant aptamer selected thus far. Circular dichroism and gel electrophoresis analyses indicate that both intramolecular and intermolecular G-quadruplex structures are populated in solution. The presence of thrombin stabilises the antiparallel intramolecular chair-like G-quadruplex conformation, that provides by far the main contribution to the biological activity of the aptamer. The crystal structure of the thrombin-oligonucleotide complex reveals that M08s-1 adopts a kinked structural organization formed by a G-quadruplex domain and a long duplex module, linked by a stretch of five purine bases. The quadruplex motif hooks the exosite I region of thrombin and the duplex region is folded towards the surface of the protein. This structural feature, which has never been observed in other anti-exosite I aptamers with a shorter duplex motif, hinders the approach of a protein substrate to the active site region and may well explain the significant increase in the anticoagulant activity of M08s-1 compared to the other anti-exosite I aptamers. Steric hindrance and structural flexibility shape the functional properties of a guanine-rich oligonucleotide.,Troisi R, Napolitano V, Rossitto E, Osman W, Nagano M, Wakui K, Popowicz GM, Yoshimoto K, Sica F Nucleic Acids Res. 2023 Sep 8;51(16):8880-8890. doi: 10.1093/nar/gkad634. PMID:37503836 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Thrombin 3D Structures

Proteopedia Page Contributors and Editors (what is this?)

OCA