Elucidation of the ATP7B N-Domain Mg2+-ATP Coordination Site and Its Allosteric Regulation

Claude Hercend (1, 2) , Cyril Bauvais (3) , Guillaume Bollot (3) , Nicolas Delacotte (3) , Philippe Chappuis (1) , France Woimant (1) , Jean-Marie Launay (1, 2) , Philippe Manivet (1, 4)

1 Hôpital Lariboisière-Fernand-Widal [APHP]
2 U942/UMR_S 942 - Biomarqueurs et insuffisance cardiaque
3 Synsight
4 SABNP - Structure et activité des biomolécules normales et pathologiques

The diagnostic of orphan genetic disease is often a puzzling task as less attention is paid to the elucidation of the pathophysiology of these rare disorders at the molecular level. We present here a multidisciplinary approach using molecular modeling tools and surface plasmonic resonance to study the function of the ATP7B protein, which is impaired in the Wilson disease. Experimentally validated in silico models allow the elucidation in the Nucleotide binding domain (N-domain) of the Mg 2+-ATP coordination site and answer to the controversial role of the Mg 2+ ion in the nucleotide binding process. The analysis of protein motions revealed a substantial effect on a long flexible loop branched to the N-domain protein core. We demonstrated the capacity of the loop to disrupt the interaction between Mg 2+-ATP complex and the N-domain and propose a role for this loop in the allosteric regulation of the nucleotide binding process.

Domains: Life Sciences [q-bio]

Claude Hercend, Cyril Bauvais, Guillaume Bollot, Nicolas Delacotte, Philippe Chappuis, et al.. Elucidation of the ATP7B N-Domain Mg2+-ATP Coordination Site and Its Allosteric Regulation. PLoS ONE, 2011, 6 (10), pp.e26245. ⟨10.1371/journal.pone.0026245⟩. ⟨hal-02321495⟩