2KOY

Structure of the E1064A mutant of the N-domain of Wilson Disease Associated Protein

Summary for 2KOY

• Entry DOI: 10.2210/pdb2koy/pdb
• Related: 2ARF
• NMR Information: BMRB: 16536
• Descriptor: Copper-transporting ATPase 2 (1 entity in total)
• Functional Keywords: atp7b, wilson disease, atpase, copper transport, atp binding, atp-binding, disease mutation, golgi apparatus, hydrolase, ion transport, magnesium, membrane, metal-binding, mitochondrion, nucleotide-binding, phosphoprotein, transmembrane, transport, metal transport
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 1
• Total formula weight: 14752.18

Authors

Dmitriev, O.Y. (deposition date: 2009-10-03, release date: 2010-12-15, Last modification date: 2024-05-22)

Primary citation

Dmitriev, O.Y.,Bhattacharjee, A.,Nokhrin, S.,Uhlemann, E.M.,Lutsenko, S.
Difference in stability of the N-domain underlies distinct intracellular properties of the E1064A and H1069Q mutants of copper-transporting ATPase ATP7B.
J. Biol. Chem., 286:16355-16362, 2011

PubMed Abstract: Wilson disease (WD) is a disorder of copper metabolism caused by mutations in the Cu-transporting ATPase ATP7B. WD is characterized by significant phenotypic variability, the molecular basis of which is poorly understood. The E1064A mutation in the N-domain of ATP7B was previously shown to disrupt ATP binding. We have now determined, by NMR, the structure of the N-domain containing this mutation and compared properties of E1064A and H1069Q, another mutant with impaired ATP binding. The E1064A mutation does not change the overall fold of the N-domain. However, the position of the α1,α2-helical hairpin (α-HH) that houses Glu(1064) and His(1069) is altered. The α-HH movement produces a more open structure compared with the wild-type ATP-bound form and misaligns ATP coordinating residues, thus explaining complete loss of ATP binding. In the cell, neither the stability nor targeting of ATP7B-E1064A to the trans-Golgi network differs significantly from the wild type. This is in a contrast to the H1069Q mutation within the same α-HH, which greatly destabilizes protein both in vitro and in cells. The difference between two mutants can be linked to a lower stability of the α-HH in the H1069Q variant at the physiological temperature. We conclude that the structural stability of the N-domain rather than the loss of ATP binding plays a defining role in the ability of ATP7B to reach the trans-Golgi network, thus contributing to phenotypic variability in WD.

PubMed: 21398519
DOI: 10.1074/jbc.M110.198101

Experimental method

SOLUTION NMR