8ALY

Cryo-EM structure of human tankyrase 2 SAM-PARP filament (G1032W mutant)

Summary for 8ALY

• Entry DOI: 10.2210/pdb8aly/pdb
• EMDB information: 15520
• Descriptor: Poly [ADP-ribose] polymerase tankyrase-2, ZINC ION (2 entities in total)
• Functional Keywords: poly-adp-ribosyltransferase, enzyme, polymer, signaling protein
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 20
• Total formula weight: 682861.54

Authors

Mariotti, L.,Inian, O.,Desfosses, A.,Beuron, F.,Morris, E.P.,Guettler, S. (deposition date: 2022-08-01, release date: 2022-11-16, Last modification date: 2024-07-24)

Primary citation

Pillay, N.,Mariotti, L.,Zaleska, M.,Inian, O.,Jessop, M.,Hibbs, S.,Desfosses, A.,Hopkins, P.C.R.,Templeton, C.M.,Beuron, F.,Morris, E.P.,Guettler, S.
Structural basis of tankyrase activation by polymerization.
Nature, 612:162-169, 2022

PubMed Abstract: The poly-ADP-ribosyltransferase tankyrase (TNKS, TNKS2) controls a wide range of disease-relevant cellular processes, including WNT-β-catenin signalling, telomere length maintenance, Hippo signalling, DNA damage repair and glucose homeostasis. This has incentivized the development of tankyrase inhibitors. Notwithstanding, our knowledge of the mechanisms that control tankyrase activity has remained limited. Both catalytic and non-catalytic functions of tankyrase depend on its filamentous polymerization. Here we report the cryo-electron microscopy reconstruction of a filament formed by a minimal active unit of tankyrase, comprising the polymerizing sterile alpha motif (SAM) domain and its adjacent catalytic domain. The SAM domain forms a novel antiparallel double helix, positioning the protruding catalytic domains for recurring head-to-head and tail-to-tail interactions. The head interactions are highly conserved among tankyrases and induce an allosteric switch in the active site within the catalytic domain to promote catalysis. Although the tail interactions have a limited effect on catalysis, they are essential to tankyrase function in WNT-β-catenin signalling. This work reveals a novel SAM domain polymerization mode, illustrates how supramolecular assembly controls catalytic and non-catalytic functions, provides important structural insights into the regulation of a non-DNA-dependent poly-ADP-ribosyltransferase and will guide future efforts to modulate tankyrase and decipher its contribution to disease mechanisms.

PubMed: 36418402
DOI: 10.1038/s41586-022-05449-8

Experimental method

ELECTRON MICROSCOPY (2.98 Å)