The crystal structure of the novel calcium-binding protein AtCBL2 from Arabidopsis thaliana.
Arabidopsis thaliana calcineurin B-like protein (AtCBL2) is a member of a recently identified family of calcineurin B-like calcium-binding proteins in A. thaliana. The crystal structure of AtCBL2 has been determined at 2.1 A resolution. The protein forms a compact alpha-helical structure with two pairs of EF-hand motifs. The structure is similar in overall folding topology to the structures of calcineurin B and neuronal calcium sensor 1, but differs significantly in local conformation. The two calcium ions are coordinated in the first and fourth EF-hand motifs, whereas the second and third EF-hand motifs are maintained in the open form by internal hydrogen bonding without coordination of calcium ions. Both a possible site and a possible mechanism for the target binding to AtCBL2 are discussed based on the three-dimensional structure.
Nagae
Masamichi
M
Graduate School of Integrated Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
Nozawa
Akira
A
Koizumi
Nozomu
N
Sano
Hiroshi
H
Hashimoto
Hiroshi
H
Sato
Mamoru
M
Shimizu
Toshiyuki
T
D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000737:chemistry*; D029681:Arabidopsis Proteins / Q000737:chemistry*; D001483:Base Sequence; D001665:Binding Sites; D019703:Calcineurin; D002135:Calcium-Binding Proteins / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D051580:Neuronal Calcium-Sensor Proteins; D009479:Neuropeptides; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
D029681:Arabidopsis Proteins; C417306:CBL protein, Arabidopsis; D002135:Calcium-Binding Proteins; D051580:Neuronal Calcium-Sensor Proteins; D009479:Neuropeptides; C101464:frequenin calcium sensor proteins; D019703:Calcineurin