The Structure and Catalytic Cycle of a Sodium-Pumping Pyrophosphatase

• DOI: 10.1126/science.1222505
• Publication Date: 2012-07-26T18:16:05Z
• Authors: Juho Kellosalo; Tommi Kajander; Konstantin Kogan; Kisun Pokharel; Adrian Goldman
• Keywords: Models, Molecular; 0303 health sciences; Protein Conformation; Hydrolysis; Cell Membrane; Molecular Sequence Data; Sodium; ta1182; Crystallography, X-Ray; Protein Structure, Secondary; Diphosphates; 03 medical and health sciences; Bacterial Proteins; Catalytic Domain; Mutation; Biocatalysis; Calcium; Magnesium; Amino Acid Sequence; Protein Multimerization; Pyrophosphatases; Hydrophobic and Hydrophilic Interactions; Ion Channel Gating

View of a Sodium Pump

Membrane-integral pyrophosphatases (M-PPases) found in plants, protozoans, bacteria, and archaea, link pyrophosphate hydrolysis or synthesis to sodium or proton pumping and contribute to generating an electrochemical potential across the membrane.

Kellosalo et al.

(p. 473 ) report the structure of the sodium pumping M-PPase from Thermotoga maritima in the resting state with product bound. The structures reveal the conformational changes that are likely to accompany pyrophosphate binding and provide insight into the ion-pumping mechanism.