Abstract: For a primitive phagocytosing cell such as the protozoan Entamoeba histolytica, dynamic fluctuations of the cytoskeleton are crucial for morphological changes involved in cellular movement as well as in phagocytosis. Both activities are implicated in the virulence of the human pathogen. Here, this study molecularly cloned an amoebic α-actinin,one of the components essential for actin bundling. The isolated cDNA codes for a protein of 537 amino acid residues, which displays two calponin homology (CH) domains and three EF-hand motifs. Although obviously belonging to the α-actinin-family, the proein has several features unusual for an α-actinin concerning its domain architecture. Structurally, this protein is the shortest member of the α-actinin family known so far.