PDBsum entry 1cm4

Calcium-binding/transferase

PDB id: 1cm4

Contents

Protein chains

143 a.a. *

18 a.a. *

Metals

_CA ×17

Waters ×58

* Residue conservation analysis

PDB id:

1cm4

Name:

Calcium-binding/transferase

Title:

Motions of calmodulin-four-conformer refinement

Structure:

Calmodulin. Chain: a. Calmodulin-dependent protein kinase ii-alpha. Chain: b. Fragment: calmodulin binding domain, residues 290 - 314. Engineered: yes

Source:

Bos taurus. Cattle. Organism_taxid: 9913. Organ: brain. Other_details: sigma lot 54h9558. Synthetic: yes

Biol. unit:

Not given

Resolution:

2.00Å R-factor: 0.166 R-free: 0.262

Authors:

M.E.Wall,G.N.Phillips Jr.

Key ref:

M.E.Wall et al. (1997). Motions of calmodulin characterized using both Bragg and diffuse X-ray scattering. Structure, 5, 1599-1612. PubMed id: 9438860 DOI: 10.1016/S0969-2126(97)00308-0

Date:

23-Sep-97 Release date: 04-Mar-98

Protein chain

P62157  (CALM_BOVIN) -  Calmodulin from Bos taurus

Seq: 149 a.a.

Struc: 143 a.a.

Protein chain

P11275  (KCC2A_RAT) -  Calcium/calmodulin-dependent protein kinase type II subunit alpha from Rattus norvegicus

Seq: 478 a.a.

Struc: 18 a.a.

Enzyme reactions

• Enzyme class: Chain B: E.C.2.7.11.17 - calcium/calmodulin-dependent protein kinase.
• Reaction:
  1. L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] + ADP + H⁺
  2. L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein] + ADP + H⁺
• Cofactor: Ca(2+)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1016/S0969-2126(97)00308-0

Structure 5:1599-1612 (1997)

PubMed id: 9438860

Motions of calmodulin characterized using both Bragg and diffuse X-ray scattering.

M.E.Wall, J.B.Clarage, G.N.Phillips.

ABSTRACT

BACKGROUND: Calmodulin is a calcium-activated regulatory protein which can bind to many different targets. The protein resembles a highly flexible dumbbell, and bends in the middle as it binds. This and other motions must be understood to formulate a realistic model of calmodulin function. RESULTS: Using the Bragg reflections from X-ray crystallography, a multiple-conformer refinement of a calmodulin-peptide complex shows anisotropic displacements, with high variations of dihedral angles in several nonhelical domains: the flexible linker; three of the four calcium-binding sites (including both of the N-terminal sites); and a turn connecting the C-terminal EF-hand calcium-binding domains. Three-dimensional maps of the large scale diffuse X-ray scattering data show isotropic liquid-like motions with an unusually small correlation length. Three-dimensional maps of the small scale diffuse streaks show highly coupled, anisotropic motions along the head-to-tail molecular packing direction in the unit cell. There is also weak coupling perpendicular to the head-to-tail packing direction, particularly across a cavity occupied by the disordered linker domain of the molecule. CONCLUSIONS: Together, the Bragg and diffuse scattering present a self-consistent description of the motions in the flexible linker of calmodulin. The other mobile regions of the protein are also of great interest. In particular, the high variations in the calcium-binding sites are likely to influence how strongly they bind ions. This is especially important in the N-terminal sites, which regulate the activity of the molecule.

Selected figure(s)

Figure 1.
Figure 1. Dynamics in calmodulin binding. The linker of calmodulin (white) bends as the ends of the protein engulf the target (red stick model); there are also significant motions within the globular ends. Experiments to characterize these motions are necessary to understand how calmodulin works (see text for details). Within the globular ends, helices are shown in cyan, b strands in green and loops in orange; Ca^2+ ions are depicted as white spheres. (The figure was made using the program RIBBONS [41].)

The above figure is reprinted by permission from Cell Press: Structure (1997, 5, 1599-1612) copyright 1997.

Figure was selected by an automated process.