A NMR study of the interaction of a three-domain construct of ATP7A with copper(I) and copper(I)-HAH1: the interplay of domains.
ATP7A is a P-type ATPase involved in copper(I) homeostasis in humans. It possesses a long N-terminal tail protruding into the cytosol and containing six copper(I)-binding domains, which are individually folded and capable of binding one copper(I) ion. ATP7A receives copper from a soluble protein, the metallochaperone HAH1. The exact role and interplay of the six soluble domains is still quite unclear, as it has been extensively demonstrated that they are strongly redundant with respect to copper(I) transport in vivo. In the present work, a three-domain (fourth to sixth, MNK456) construct has been investigated in solution by NMR, in the absence and presence of copper(I). In addition, the interaction of MNK456 with copper(I)-HAH1 has been studied. It is proposed that the fourth domain is the preferential site for the initial interaction with the partner. A significant dependence of the overall domain dynamics on the metallation state and on the presence of HAH1 is observed. This dependence could constitute the molecular mechanism to trigger copper(I) translocation and/or ATP7A relocalization from the trans-Golgi network to the plasmatic membrane.
Banci
Lucia
L
Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy.
Bertini
Ivano
I
Cantini
Francesca
F
Chasapis
Christos T
CT
Hadjiliadis
Nick
N
Rosato
Antonio
A
D000251:Adenosine Triphosphatases / Q000737:chemistry*; D001665:Binding Sites; D027682:Cation Transport Proteins / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003300:Copper / Q000737:chemistry*; D000079922:Copper Transport Proteins; D000073840:Copper-Transporting ATPases; D003545:Cysteine / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D006056:Golgi Apparatus / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D056511:Metallochaperones; D015233:Models, Statistical; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry*; D013997:Time Factors
C474500:ATOX1 protein, human; D027682:Cation Transport Proteins; D000079922:Copper Transport Proteins; D056511:Metallochaperones; D018832:Molecular Chaperones; D011993:Recombinant Fusion Proteins; D003300:Copper; D000251:Adenosine Triphosphatases; C081184:ATP7A protein, human; D000073840:Copper-Transporting ATPases; D003545:Cysteine