 |
PDBsum entry 2chd
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Protein transport
|
PDB id
|
|
|
|
2chd
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Structure of the c2a domain of rabphilin-3a.
|
|
|
Authors
|
|
M.Biadene,
P.Montaville,
G.M.Sheldrick,
S.Becker.
|
|
|
Ref.
|
|
Acta Crystallogr D Biol Crystallogr, 2006,
62,
793-799.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Rabphilin-3A is a neuronal protein containing a C2-domain tandem. To date, only
the structure of the C2B domain has been solved. The crystal structure of the
Ca2+-free C2A domain has been solved by molecular replacement and refined to
1.92 A resolution. It adopts the classical C2-domain fold consisting of an
eight-stranded antiparallel beta-sandwich with type I topology. In agreement
with its Ca2+-dependent negatively charged membrane-binding properties, this C2
domain contains all the conserved acidic residues responsible for calcium
binding. However, the replacement of a conserved aspartic acid residue by
glutamic acid allows formation of an additional strong hydrogen bond, resulting
in increased rigidity of calcium-binding loop 1. The electrostatic surface of
the C2A domain consists of a large positively charged belt surrounded by two
negatively charged patches located at both tips of the domain. In comparison,
the structurally very similar C2A domain of synaptotagmin I has a highly acidic
electrostatic surface, suggesting completely unrelated functions for these two
C2A domains.
|
|
|
|
|
|
|
|
Figure 2.
Figure 2 Overall structure of the C2A domain of rabphilin-3A.
(a) Cartoon drawing showing the common eight-stranded
antiparallel  -sandwich.
(b) Topology diagram (made with the program TOPDRAW; Bond,
2003[Bond, C. S. (2003). Bioinformatics, 19, 311-312.]).
|
|
Figure 3.
Figure 3 Residues in the Ca^2+-binding region: the residues of
the C2A domain of rabphilin-3A are coloured green and the
residues of synaptotagmin I and the Ca^2+ ions present in that
structure (PDB code 1byn ) are coloured blue.
|
|
|
|
|
|
The above figures are
reprinted
by permission from the IUCr:
Acta Crystallogr D Biol Crystallogr
(2006,
62,
793-799)
copyright 2006.
|
|
|
|
|
|
|
