Nucleotide recognition by CopA, a Cu+-transporting P-type ATPase.
Heavy metal pumps constitute a large subgroup in P-type ion-transporting ATPases. One of the outstanding features is that the nucleotide binding N-domain lacks residues critical for ATP binding in other well-studied P-type ATPases. Instead, they possess an HP-motif and a Gly-rich sequence in the N-domain, and their mutations impair ATP binding. Here, we describe 1.85 A resolution crystal structures of the P- and N-domains of CopA, an archaeal Cu(+)-transporting ATPase, with bound nucleotides. These crystal structures show that CopA recognises the adenine ring completely differently from other P-type ATPases. The crystal structure of the His462Gln mutant, in the HP-motif, a disease-causing mutation in human Cu(+)-ATPases, shows that the Gln side chain mimics the imidazole ring, but only partially, explaining the reduction in ATPase activity. These crystal structures lead us to propose a role of the His and a mechanism for removing Mg(2+) from ATP before phosphoryl transfer.
Tsuda
Takeo
T
Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan.
Toyoshima
Chikashi
C
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D019943:Amino Acid Substitution; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism*; D019611:Archaeoglobus fulgidus / Q000201:enzymology*; D001665:Binding Sites; D027682:Cation Transport Proteins / Q000378:metabolism*; D000073840:Copper-Transporting ATPases; D018360:Crystallography, X-Ray; D017136:Ion Transport; D008958:Models, Molecular; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism
D019843:Archaeal Proteins; D027682:Cation Transport Proteins; D050505:Mutant Proteins; D010455:Peptides; D021122:Protein Subunits; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases