Structure of the catalytic nucleotide-binding subunit A of A-type ATP synthase from Pyrococcus horikoshii reveals a novel domain related to the peripheral stalk.
H(+)-transporting ATP synthase is a multi-subunit enzyme involved in the production of ATP, which is an essential molecule for living organisms as a source of energy. Archaeal A-type ATPase (A-ATPase) is thought to act as a functional ATP synthase in archaea and is thought to have chimeric properties of F-ATPase and V-ATPase. Previous structural studies of F-ATPase indicated that the major nucleotide-binding subunits alpha and beta consist of three domains. The catalytic nucleotide-binding subunit A of V/A-ATPase contains an insertion of about 90 residues which is absent from the F(1)-ATPase beta subunit. Here, the first X-ray structure of the catalytic nucleotide-binding subunit A of an A(1)-ATPase is described, determined at 2.55 A resolution. A(1)-ATPase subunit A from Pyrococcus horikoshii consists of four domains. A novel domain, including part of the insertion, corresponds to the 'knob-like structure' observed in electron microscopy of A(1)-ATPase. Based on the structure, it is highly likely that this inserted domain is related to the peripheral stalk common to the A- and V-ATPases. The arrangement of this inserted domain suggests that this region plays an important role in A-ATPase as well as in V-ATPase.
Maegawa
Yuki
Y
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Japan.
Morita
Hazuki
H
Iyaguchi
Daisuke
D
Yao
Min
M
Watanabe
Nobuhisa
N
Tanaka
Isao
I
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000737:chemistry; D021122:Protein Subunits / Q000737:chemistry; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000378:metabolism; D043902:Pyrococcus horikoshii / Q000201:enzymology*
D019843:Archaeal Proteins; D009711:Nucleotides; D021122:Protein Subunits; D006180:Proton-Translocating ATPases