Crystallization and preliminary X-ray crystallographic analysis of macrophage/microglia-specific calcium-binding protein Iba1

Iba1 (ionized calcium-binding adaptor molecule 1) is expressed specifically in macrophages/microglia and is involved in the activation of Rac, coordinating the reorganization of the actin cytoskeleton followed by the formation of lamellipodia and membrane ruffles, which are typical properties of activated microglia. Human Iba1 and mouse Iba1 were overexpressed and crystallized. The crystals belong to a monoclinic system, with space group C2 and unit-cell parameters a = 60.75, b = 36.61, c = 99.71 Å, β = 99.71° for human Iba1 and a = 76.28, b = 44.06, c = 99.13 Å, β = 90.03° for mouse Iba1. Both crystals diffracted well to a resolution of 2.1 Å and initial phase determinations were attempted by a molecular-replacement method using calmodulin structures.