 |
PDBsum entry 4mlw
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Metal binding protein
|
PDB id
|
|
|
|
4mlw
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
A highly conserved cysteine of neuronal calcium-Sensing proteins controls cooperative binding of ca2+ to recoverin.
|
|
|
Authors
|
|
M.J.Ranaghan,
R.P.Kumar,
K.S.Chakrabarti,
V.Buosi,
D.Kern,
D.D.Oprian.
|
|
|
Ref.
|
|
J Biol Chem, 2013,
288,
36160-36167.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Recoverin, a 23-kDa Ca(2+)-binding protein of the neuronal calcium sensing (NCS)
family, inhibits rhodopsin kinase, a Ser/Thr kinase responsible for termination
of photoactivated rhodopsin in rod photoreceptor cells. Recoverin has two
functional EF hands and a myristoylated N terminus. The myristoyl chain imparts
cooperativity to the Ca(2+)-binding sites through an allosteric mechanism
involving a conformational equilibrium between R and T states of the protein.
Ca(2+) binds preferentially to the R state; the myristoyl chain binds
preferentially to the T state. In the absence of myristoylation, the R state
predominates, and consequently, binding of Ca(2+) to the non-myristoylated
protein is not cooperative. We show here that a mutation, C39A, of a highly
conserved Cys residue among NCS proteins, increases the apparent cooperativity
for binding of Ca(2+) to non-myristoylated recoverin. The binding data can be
explained by an effect on the T/R equilibrium to favor the T state without
affecting the intrinsic binding constants for the two Ca(2+) sites.
|
|
|
|
|
|
|
