5LG7

Solution NMR structure of Tryptophan to Arginine mutant of Arkadia RING domain

Summary for 5LG7

• Entry DOI: 10.2210/pdb5lg7/pdb
• Related: 2KIZ 5LG0
• NMR Information: BMRB: 25248
• Descriptor: E3 ubiquitin-protein ligase Arkadia, ZINC ION (2 entities in total)
• Functional Keywords: arkadia, rnf111, e3 ubiquitin ligase, ring domain, tryptophan, tgf-b, ubch5b, e2 enzyme, ligase
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 1
• Total formula weight: 8061.84

Authors

Birkou, M.,Chasapis, C.T.,Loutsidou, A.K.,Bentrop, D.,Lelli, M.,Herrmann, T.,Episkopou, V.,Spyroulias, G.A. (deposition date: 2016-07-06, release date: 2017-06-28, Last modification date: 2024-11-13)

Primary citation

Birkou, M.,Chasapis, C.T.,Marousis, K.D.,Loutsidou, A.K.,Bentrop, D.,Lelli, M.,Herrmann, T.,Carthy, J.M.,Episkopou, V.,Spyroulias, G.A.
A Residue Specific Insight into the Arkadia E3 Ubiquitin Ligase Activity and Conformational Plasticity.
J. Mol. Biol., 429:2373-2386, 2017

PubMed Abstract: Arkadia (Rnf111) is an E3 ubiquitin ligase that plays a central role in the amplification of transforming growth factor beta (TGF-β) signaling responses by targeting for degradation the negative regulators of the pathway, Smad6 and Smad7, and the nuclear co-repressors Ski and Skil (SnoN). Arkadia's function in vivo depends on the really interesting new gene (RING)-H2 interaction with the E2 enzyme UbcH5b in order to ligate ubiquitin chains on its substrates. A conserved tryptophan (W972) in the C-terminal α-helix is widely accepted as essential for E2 recruitment and interaction and thus also for E3 enzymatic activity. The present NMR-driven study provides an atomic-level investigation of the structural and dynamical properties of two W972 Arkadia RING mutants, attempting to illuminate for the first time the differences between a functional and a nonfunctional mutant W972A and W972R, respectively. A TGF-β-responsive promoter driving luciferase was used to assay for Arkadia function in vivo. These experiments showed that the Arkadia W972A mutant has the same activity as wild-type (WT) Arkadia in enhancing TGF-β signaling responses, while W972R does not. Only minor structural differences exist between the W972A RING domain and WT-RING. In contrast, the W972R mutant hardly interacts with E2. The loss of function correlates with structural changes in the C-terminal α-helix and an increase in the distance between the Zn(II) ions. Our data show that the position occupied by W972 within WT Arkadia is critical for the function of RING and that it depends on the nature of the residue at this position.

PubMed: 28647409
DOI: 10.1016/j.jmb.2017.06.012

Experimental method

SOLUTION NMR