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Structure and interactions of the C‐terminal metal binding domain of Archaeoglobus fulgidus CopA
Author(s) -
Agarwal Sorabh,
Hong Deli,
Desai Nirav K.,
Sazinsky Matthew H.,
Argüello José M.,
Rosenzweig Amy C.
Publication year - 2010
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.22753
Subject(s) - dimer , chemistry , atp hydrolysis , crystallography , atpase , c terminus , protein structure , integral membrane protein , p type atpase , biochemistry , biophysics , stereochemistry , membrane , membrane protein , biology , amino acid , enzyme , organic chemistry
The Cu + ‐ATPase CopA from Archaeoglobus fulgidus belongs to the P 1B family of the P‐type ATPases. These integral membrane proteins couple the energy of ATP hydrolysis to heavy metal ion translocation across membranes. A defining feature of P 1B‐1 ‐type ATPases is the presence of soluble metal binding domains at the N‐terminus (N‐MBDs). The N‐MBDs exhibit a conserved ferredoxin‐like fold, similar to that of soluble copper chaperones, and bind metal ions via a conserved CXXC motif. The N‐MBDs enable Cu + regulation of turnover rates apparently through Cu‐sensitive interactions with catalytic domains. A. fulgidus CopA is unusual in that it contains both an N‐terminal MBD and a C‐terminal MBD (C‐MBD). The functional role of the unique C‐MBD has not been established. Here, we report the crystal structure of the apo, oxidized C‐MBD to 2.0 Å resolution. In the structure, two C‐MBD monomers form a domain‐swapped dimer, which has not been observed previously for similar domains. In addition, the interaction of the C‐MBD with the other cytoplasmic domains of CopA, the ATP binding domain (ATPBD) and actuator domain (A‐domain), has been investigated. Interestingly, the C‐MBD interacts specifically with both of these domains, independent of the presence of Cu + or nucleotides. These data reinforce the uniqueness of the C‐MBD and suggest a distinct structural role for the C‐MBD in CopA transport. Proteins 2010. © 2010 Wiley‐Liss, Inc.