PDBsum entry 1yx8

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protein links
Metal binding protein PDB id
Protein chain
83 a.a. *
* Residue conservation analysis
PDB id:
Name: Metal binding protein
Title: Nmr structure of calsensin, 20 low energy structures.
Structure: Calsensin. Chain: a. Synonym: lan3-6 antigen. Engineered: yes
Source: Haemopis marmorata. Organism_taxid: 38567. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.
NMR struc: 20 models
Authors: D.V.Venkitaramani,D.B.Fulton,A.H.Andreotti,K.M.Johansen, J.Johansen
Key ref:
D.V.Venkitaramani et al. (2005). Solution structure and backbone dynamics of Calsensin, an invertebrate neuronal calcium-binding protein. Protein Sci, 14, 1894-1901. PubMed id: 15937283 DOI: 10.1110/ps.051412605
19-Feb-05     Release date:   05-Apr-05    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
Q25088  (CLSS_HAEMA) -  Calsensin
83 a.a.
83 a.a.
Key:    PfamA domain  Secondary structure

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     cytoplasm   1 term 
  Biochemical function     metal ion binding     2 terms  


DOI no: 10.1110/ps.051412605 Protein Sci 14:1894-1901 (2005)
PubMed id: 15937283  
Solution structure and backbone dynamics of Calsensin, an invertebrate neuronal calcium-binding protein.
D.V.Venkitaramani, D.B.Fulton, A.H.Andreotti, K.M.Johansen, J.Johansen.
Calsensin is an EF-hand calcium-binding protein expressed by a subset of peripheral sensory neurons that fasciculate into a single tract in the leech central nervous system. Calsensin is a 9-kD protein with two EF-hand calcium-binding motifs. Using multidimensional NMR spectroscopy we have determined the solution structure and backbone dynamics of calcium-bound Calsensin. Calsensin consists of four helices forming a unicornate-type four-helix bundle. The residues in the third helix undergo slow conformational exchange indicating that the motion of this helix is associated with calciumbinding. The backbone dynamics of the protein as measured by (15)N relaxation rates and heteronuclear NOEs correlate well with the three-dimensional structure. Furthermore, comparison of the structure of Calsensin with other members of the EF-hand calcium-binding protein family provides insight into plausible mechanisms of calcium and target protein binding.
  Selected figure(s)  
Figure 1.
Figure 1. (A) Overlay of the 20 lowest energy structures of Calsensin. The structures were superimposed using all the backbone residues in the secondary structural elements and rendered using MOLMOL. The N-terminal residues M1-K6 and C-terminal Q81- K83 were not assigned due to lack of sequential NOEs. All the helices are well-defined except for H3, which shows chemical exchange and higher RMSD as compared to the mean structure. (B) Surface plot of Calsensin rendered using MOLMOL. The regions colored in blue have positive electrostatic potential, those colored in red have negative electrostatic potential, and the regions in white are nonpolar. The hydrophobic residues in the helices 2, 3, and 4 as well as in the hinge region are exposed to the surface. (C) Stereo view of the energy minimized average ribbon structure of Calsensin. The labeling of the secondary structural elements follows the standard nomenclature used for EF-hand calcium-binding proteins. (D) Alignment of Calsensin with other members of the EF-hand family of calcium binding proteins. The sequence of Calsensin was aligned with CaM, Plastin-1 and with the members of S100 and polcalcin families. The alignment was generated using AlignX software of the VectorNTI Suite from Invitrogen. The residues in Calsensin that are identical are highlighted in yellow (polcalcin family) or cyan (other EF-hand members), while similar residues are shown in red. The two highly conserved aspartic acid residues are shown in red and highlighted in gray.
  The above figure is reprinted by permission from the Protein Society: Protein Sci (2005, 14, 1894-1901) copyright 2005.  
  Figure was selected by an automated process.