1n0y

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Revision as of 19:44, 20 November 2007

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spinqualitylabelsall models 1n0y, resolution 1.75Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal Structure of Pb-bound Calmodulin

Overview

Calmodulin (CaM) regulates a variety of cellular processes by interacting, with a large number of proteins in a Ca(2+)-dependent manner., Conformational flexibility plays a key role in CaM function, although the, full extent and detailed features of this flexibility are not fully, characterized. Here, the 1.75 A resolution crystal structure of, Pb(2+)-bound Paramecium tetraurelia CaM crystallized in a previously, unobserved monoclinic lattice is reported. Pb(2+)-CaM is disordered in, this new lattice and only a portion of each of the two molecules in the, asymmetric unit can be modeled. Comparison of the structures of Ca(2+)-CaM, and Pb(2+)-CaM show close agreement in the C-terminal domain but, significant structural differences in the N-terminal domain. In addition, translation-libration-screw (TLS) refinement and Rosenfield difference, analysis reveal inter-helical flexibility in the metal-bound N-terminal, domain of the protein that is absent in the metal-bound C-terminal domain, and indicates that the two structurally similar domains of CaM are, dynamically distinct. These results demonstrate that TLS refinement and, Rosenfield difference analysis allow detailed information about, macromolecular flexibility to be extracted from X-ray diffraction data, even when the crystal lattice prohibits full manifestation of this, flexibility.

About this Structure

1N0Y is a Single protein structure of sequence from Paramecium tetraurelia with PB, CAC and ACT as ligands. Full crystallographic information is available from OCA.

Reference

Domain flexibility in the 1.75 A resolution structure of Pb2+-calmodulin., Wilson MA, Brunger AT, Acta Crystallogr D Biol Crystallogr. 2003 Oct;59(Pt 10):1782-92. Epub 2003, Sep 19. PMID:14501118

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