The hydrogen bonds between Arg(super 423) and Glu(super 472) and other key residues, Asp(super 443), Ser(super 477) and Pro(super 489) are responsible for the formation and a different positioning of TNP-ATP and ATP within the nucleotide-binding site of Na(super +)/K(super +)-Atpase

On the basis of the computer model, it is hypothesized that a hydrogen bond between Arg423 and Glu497 supports the connection of two opposite halves of the ATP-binding pocket. This strongly supported the existence of the hydrogen bond between Arg(super 423) and Glu(super 472).