Structure of the rotor of the V-Type Na+-ATPase from Enterococcus hirae.

TitleStructure of the rotor of the V-Type Na+-ATPase from Enterococcus hirae.
Publication TypeJournal Article
Year of Publication2005
AuthorsMurata, T, Yamato, I, Kakinuma, Y, Leslie, AGW, Walker, JE
Date Published2005 Apr 29
KeywordsAdenosine Triphosphatases, Adenosine Triphosphate, Amino Acid Sequence, Bacterial Proteins, Binding Sites, Crystallography, X-Ray, Detergents, Enterococcus, Ion Transport, Models, Biological, Models, Molecular, Molecular Motor Proteins, Molecular Sequence Data, Phospholipids, Protein Conformation, Protein Structure, Tertiary, Protein Subunits, Sodium, Static Electricity, Water

The membrane rotor ring from the vacuolar-type (V-type) sodium ion-pumping adenosine triphosphatase (Na+-ATPase) from Enterococcus hirae consists of 10 NtpK subunits, which are homologs of the 16-kilodalton and 8-kilodalton proteolipids found in other V-ATPases and in F1Fo- or F-ATPases, respectively. Each NtpK subunit has four transmembrane alpha helices, with a sodium ion bound between helices 2 and 4 at a site buried deeply in the membrane that includes the essential residue glutamate-139. This site is probably connected to the membrane surface by two half-channels in subunit NtpI, against which the ring rotates. Symmetry mismatch between the rotor and catalytic domains appears to be an intrinsic feature of both V- and F-ATPases.

Alternate JournalScience
Citation Key10.1126/science.1110064
PubMed ID15802565