title: Alpha-lactalbumin possesses a novel calcium binding loop.
abstract: Calcium performs a unique role in biology, achieving biological effects through highly specific interactions with and modulation of target proteins. It has been proposed that calcium-modulated proteins possess a characteristic, evolutionarily related, binding fold, known as the EF-hand. The high-resolution X-ray structure of alpha-lactalbumin reveals a Ca2+ binding fold that resembles an EF-hand only superficially and presumably has no evolutionary relationship with it. However, there is clear homology with the corresponding loop in c-type lysozyme (the 'parent' molecule of alpha-lactalbumin). This study, at 1.7 A resolution, represents one of the most accurate analyses of a calcium binding protein yet reported.
mesh_terms: D001665:Binding Sites; D005075:Biological Evolution; D002135:Calcium-Binding Proteins; D007768:Lactalbumin; D008958:Models, Molecular; D009113:Muramidase; D014961:X-Ray Diffraction
chemical_list: D002135:Calcium-Binding Proteins; D007768:Lactalbumin; D009113:Muramidase