Secondary structure of a calcium binding protein (CaBP) from Entamoeba histolytica

A calcium binding protein from Entamoeba histolytica, (EhCaBP, M-r similar to 15 kDa) is the causative agent for amoebiosis and has a very low sequenc e homology (similar to 30%) with other known CaBPs, Almost complete sequenc e specific resonance assignments for H-1, C-13 and N-15 spins in EhCaBP wer e obtained using double and triple resonance NMR experiments, Qualitative i nterpretation of the nuclear Overhauser enhancements, chemical shift indice s and of hydrogen exchange rates threw valuable light upon the secondary st ructure of this protein. CaBP is found to have two globular domains each of which consists of two pairs of helix-loop-helix motifs, Though this protei n has a very small sequence homology with calmodulins, the topological arra ngement of the alpha-helices and beta-strands in EhCaBP resemble them, (C) 1999 Federation of European Biochemical Societies.