Crystal structure of recombinant bovine neurocalcin.
Department of Biochemistry, Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
The crystal structure of calcium-bound unmyristoylated bovine neurocalcin from Escherichia coli has been determined at 2.4 A resolution. The three-dimensional structure reveals a highly compact structure consisting of: (i) two pairs of calcium-binding EF-hands (EF1-EF2 and EF3-EF4); (ii) a calcium ion bound at EF2, EF3 and EF4 sites; and (iii) an EF1-hand that is disabled from calcium-binding due to a Cys-Pro sequence in the Ca2+-binding loop. The crystal structure of neurocalcin resembles photoreceptor recoverin in overall topology, however its EF2- and EF4-hands differ. Recently, neurocalcin in the calcium-bound state has been shown to stimulate mammalian rod outer segment membrane guanylate cyclase. A possible site for cyclase activity based on the three-dimensional structure is discussed.
PMID: 9886296 [PubMed - indexed for MEDLINE]