A protein complex that possesses hydrogen:potassium-exchanging ATPase activity; characterized in animal cells, where it maintains ionic gradients of K+ at the expense of ATP hydrolysis; The complex contains two obligatory subunits, the catalytic alpha subunit and a glycosylated beta subunit; two additional subunits, gamma and channel-inducing factor (CHIF), may also be present. [ http://www.ncbi.nlm.nih.gov/pubmed/11756431 ]