The crystal structure of the novel calcium-binding protein AtCBL2 from Arabidopsis thaliana

J Biol Chem. 2003 Oct 24;278(43):42240-6. doi: 10.1074/jbc.M303630200. Epub 2003 Jul 19.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Arabidopsis / chemistry*
  • Arabidopsis Proteins / chemistry*
  • Base Sequence
  • Binding Sites
  • Calcineurin
  • Calcium-Binding Proteins / chemistry*
  • Crystallization
  • Crystallography, X-Ray
  • Hydrogen Bonding
  • Models, Molecular
  • Neuronal Calcium-Sensor Proteins
  • Neuropeptides
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Sequence Alignment

Substances

  • Arabidopsis Proteins
  • CBL protein, Arabidopsis
  • Calcium-Binding Proteins
  • Neuronal Calcium-Sensor Proteins
  • Neuropeptides
  • frequenin calcium sensor proteins
  • Calcineurin