PDBsum entry 2sas

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Calcium-binding protein PDB id
Protein chain
185 a.a. *
_CA ×3
Waters ×1
* Residue conservation analysis
PDB id:
Name: Calcium-binding protein
Title: Structure of a sarcoplasmic calcium-binding protein from amphioxus refined at 2.4 angstroms resolution
Structure: Sarcoplasmic calcium-binding protein. Chain: a. Engineered: yes
Source: Branchiostoma lanceolatum. Amphioxus. Organism_taxid: 7740
Biol. unit: Dimer (from PQS)
2.40Å     R-factor:   0.199    
Authors: W.J.Cook,Y.S.Babu,J.A.Cox
Key ref: W.J.Cook et al. (1993). Structure of a sarcoplasmic calcium-binding protein from amphioxus refined at 2.4 A resolution. J Mol Biol, 229, 461-471. PubMed id: 8429557
30-Jul-93     Release date:   31-Oct-93    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
P04570  (SCP2_BRALA) -  Sarcoplasmic calcium-binding proteins II, V, VI, and VII
185 a.a.
185 a.a.
Key:    PfamA domain  PfamB domain  Secondary structure  CATH domain

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biochemical function     metal ion binding     2 terms  


J Mol Biol 229:461-471 (1993)
PubMed id: 8429557  
Structure of a sarcoplasmic calcium-binding protein from amphioxus refined at 2.4 A resolution.
W.J.Cook, L.C.Jeffrey, J.A.Cox, S.Vijay-Kumar.
The three-dimensional structure of a sarcoplasmic Ca(2+)-binding protein from the protochordate amphioxus has been determined at 2.4 A resolution using multiple-isomorphous-replacement techniques. The refined model includes all 185 residues, three calcium ions, and one water molecule. The final crystallographic R-factor is 0.199. Bond lengths and bond angles in the molecules have root-mean-square deviations from ideal values of 0.015 A and 2.8 degrees, respectively. The overall structure is highly compact and globular with a predominantly hydrophobic core, unlike the extended dumbbell-shaped structures of calmodulin or troponin C. There are four distinct domains with the typical helix-loop-helix Ca(2+)-binding motif (EF hand). The conformation of the pair of EF hands in the N-terminal half of the protein is unusual due to the presence of an aspartate residue in the twelfth position of the first Ca(2+)-binding loop, rather than the usual glutamate. The C-terminal half of the molecule contains one Ca(2+)-binding domain with a novel helix-loop-helix conformation and one Ca(2+)-binding domain that is no longer functional because of amino acid changes. The overall structure is quite similar to a sarcoplasmic Ca(2+)-binding protein from sandworm, although there is only about 12% amino acid sequence identity between them. The similarity of the structures of these two proteins suggests that all sarcoplasmic Ca(2+)-binding proteins will have the same general conformation, even though there is very little conservation of primary structure among the proteins from various species.

Literature references that cite this PDB file's key reference

  PubMed id Reference
17989881 J.Luan, S.Zhang, Z.Liu, C.Fan, G.Ji, and L.Li (2007).
Characterization, evolution and tissue-specific expression of AmphiCalbin, a novel gene encoding EF-hand calcium-binding protein in amphioxus Branchiostoma belcheri.
  Acta Biochim Biophys Sin (Shanghai), 39, 891-900.  
15819893 G.Rabah, R.Popescu, J.A.Cox, Y.Engelborghs, and C.T.Craescu (2005).
Solution structure and internal dynamics of NSCP, a compact calcium-binding protein.
  FEBS J, 272, 2022-2036.
PDB code: 1q80
12755706 H.Tossavainen, P.Permi, A.Annila, I.Kilpeläinen, and T.Drakenberg (2003).
NMR solution structure of calerythrin, an EF-hand calcium-binding protein from Saccharopolyspora erythraea.
  Eur J Biochem, 270, 2505-2512.
PDB code: 1nya
11266596 H.Aitio, T.Laakso, T.Pihlajamaa, M.Torkkeli, I.Kilpeläinen, T.Drakenberg, R.Serimaa, and A.Annila (2001).
Characterization of apo and partially saturated states of calerythrin, an EF-hand protein from S. erythraea: a molten globule when deprived of Ca(2+).
  Protein Sci, 10, 74-82.  
10822252 P.M.Hwang, and H.J.Vogel (2000).
Structures of the platelet calcium- and integrin-binding protein and the alphaIIb-integrin cytoplasmic domain suggest a mechanism for calcium-regulated recognition; homology modelling and NMR studies.
  J Mol Recognit, 13, 83-92.
PDB codes: 1dgu 1dgv
10757969 S.Y.Lee, and R.E.Klevit (2000).
The whole is not the simple sum of its parts in calmodulin from S. cerevisiae.
  Biochemistry, 39, 4225-4230.  
  10631973 H.Aitio, A.Annila, S.Heikkinen, E.Thulin, T.Drakenberg, and I.Kilpeläinen (1999).
NMR assignments, secondary structure, and global fold of calerythrin, an EF-hand calcium-binding protein from Saccharopolyspora erythraea.
  Protein Sci, 8, 2580-2588.  
  9041633 P.Groves, S.Linse, E.Thulin, and S.Forsén (1997).
A calbindin D9k mutant containing a novel structural extension: 1H nuclear magnetic resonance studies.
  Protein Sci, 6, 323-330.  
  9236210 S.K.Drake, M.A.Zimmer, C.Kundrot, and J.J.Falke (1997).
Molecular tuning of an EF-hand-like calcium binding loop. Contributions of the coordinating side chain at loop position 3.
  J Gen Physiol, 110, 173-184.  
  9385641 S.Linse, E.Thulin, L.K.Gifford, D.Radzewsky, J.Hagan, R.R.Wilk, and K.S.Akerfeldt (1997).
Domain organization of calbindin D28k as determined from the association of six synthetic EF-hand fragments.
  Protein Sci, 6, 2385-2396.  
9053397 W.D.Kohn, C.T.Mant, and R.S.Hodges (1997).
Alpha-helical protein assembly motifs.
  J Biol Chem, 272, 2583-2586.  
8548446 R.H.Kretsinger, and R.H.Kretsinger (1996).
EF-hands reach out.
  Nat Struct Biol, 3, 12-15.  
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