Crystallization and preliminary X-ray analysis of full-length annexin I comprising the core and N-terminal domain

Annexin I, a member of the annexin family of Ca(2+)- and phospholipid-binding proteins, has been crystallized with the complete N-terminus. Annexins are structurally divided into a conserved protein core and an N-terminal domain that is variable in sequence and length. Three-dimensional structures of annexins comprising the protein core and a short N-terminal domain (annexins III, IV, V, VI, XII) or a truncated form almost completely lacking the N-terminal domain (annexins I and II) have been published so far. Here, the crystallization of annexin I comprising not only the core but also the complete N-terminal domain is reported. The crystals belong to the space group P2(1)2(1)2(1), with unit-cell parameters a = 63.6, b = 96.3, c = 127.4 A, and diffract to better than 2 A. Assuming a molecular weight of 38.7 kDa for annexin I and an average value of 2.5 A(3) Da(-1) for V(M), two molecules per asymmetric unit are present.