Human TIGAR protein consists of 270 arninoacids, with a molecular weight of 30063 Da. It is cornposed of a bisphosphatase active site in which two histidines, His-11 and His-198, and one glutamic acid, Glu-1 02, are key residues for its function TIGAR catalytic domain belongs to the histidine phosphatase superfamily of proteins, a conserved group of proteins which contain a domain with a histidine forming a phosphoenzyme transiently during the catalysis (Rigden, 2008). This domain shares similarity with enzymes ofthe phosphoglycerate rrutase fumily (PGAM) and with the bisphosphatase domain of6-phosphofructo-2-kinase/:6:uctose-2,6-bisphosphatase (PFK-2/FBPase- 2.), in which the three aminoacids in the catalytic domain are conserved. More infurmation about TIGAR protein can be found in Uniprot 0 9N088. Human TIGAR structure contains different motifs as represented in the image below (PDB reference 3DCY). The crystallized structure of Danio rerio TIGAR is available inPDB (3E9D rererence) and was published by Li and Jogl, 2009.