title: Secondary structure of a calcium binding protein (CaBP) from Entamoeba histolytica.
abstract: A calcium binding protein from Entamoeba histolytica, (EhCaBP, M(r) approximately 15 kDa) is the causative agent for amoebiosis and has a very low sequence homology (approximately 30%) with other known CaBPs. Almost complete sequence specific resonance assignments for (1)H, (13)C and (15)N spins in EhCaBP were obtained using double and triple resonance NMR experiments. Qualitative interpretation of the nuclear Overhauser enhancements, chemical shift indices and of hydrogen exchange rates threw valuable light upon the secondary structure 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 protein has a very small sequence homology with calmodulins, the topological arrangement of the alpha-helices and beta-strands in EhCaBP resemble them.
authors.affiliation: Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India.
authors.forename: S C
authors.initials: SC
authors.lastname: Sahu
authors.forename: A
authors.initials: A
authors.lastname: Bhattacharya
authors.forename: K V
authors.initials: KV
authors.lastname: Chary
authors.forename: G
authors.initials: G
authors.lastname: Govil
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry*; D002147:Calmodulin / Q000737:chemistry; D003903:Deuterium / Q000737:chemistry; D004748:Entamoeba histolytica / Q000737:chemistry*; D018257:Helix-Loop-Helix Motifs; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid
chemical_list: D002135:Calcium-Binding Proteins; D002147:Calmodulin; D003903:Deuterium; D002118:Calcium