“…The gastric proton pump plays an important role in the pathology of peptic ulcer disease and is a well-established therapeutic target [2]. Proton pump inhibitors are widely recognized as important drug candidates [3] as testified by the high share of the pharmaceutical market held by the anti-ulcer drug, omeprazole. Determining the three-dimensional structure of inhibitors at the active site of a therapeutic target like the gastric proton pump can provide a rationale for the design of novel drugs [4,5].…”