 |
PDBsum entry 1i3h
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Sugar binding protein
|
PDB id
|
|
|
|
1i3h
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
* Residue conservation analysis
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
The 1.2 a resolution structure of the con a-Dimannose complex.
|
|
|
Authors
|
|
D.A.Sanders,
D.N.Moothoo,
J.Raftery,
A.J.Howard,
J.R.Helliwell,
J.H.Naismith.
|
|
|
Ref.
|
|
J Mol Biol, 2001,
310,
875-884.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
The complex between concanavalin A (Con A) and alpha1-2 mannobiose (mannose
alpha1-2 mannose) has been refined to 1.2 A resolution. This is the highest
resolution structure reported for any sugar-lectin complex. As the native
structure of Con A to 0.94 A resolution is already in the database, this gives
us a unique opportunity to examine sugar-protein binding at high resolution.
These data have allowed us to model a number of hydrogen atoms involved in the
binding of the sugar to Con A, using the difference density map to place the
hydrogen atoms. This map reveals the presence of the protonated form of Asp208
involved in binding. Asp208 is not protonated in the 0.94 A native structure.
Our results clearly show that this residue is protonated and hydrogen bonds to
the sugar. The structure accounts for the higher affinity of the alpha1-2 linked
sugar when compared to other disaccharides. This structure identifies different
interactions to those predicted by previous modelling studies. We believe that
the additional data presented here will enable significant improvements to be
made to the sugar-protein modelling algorithms.
|
|
|
|
|
|
|
|
Figure 1.
Figure 1. Schematic representation of binding of
Man-(a1-2)Man to Con A. Structural water[4] labelled as Wat30.
The two conformations for Arg228 (see text and Figure 2) are
displayed, with the second conformation designated (Alt). Figure
generated using LIGPLOT.[36]
|
|
Figure 2.
Figure 2. Stereo view of final 2F[o] - F[c] map showing the
alternate conformations adopted by Arg228. The density was
modelled at 2 r.m.s. Oxygen atoms are coloured red, nitrogen
atoms blue, sulphur atoms yellow and carbon atoms grey. All
molecular representations generated using BOBSCRIPT[37]
utilizing the GL_RENDER interface (L. Esser & J. Deisenhofer,
unpublished data) and POV-Ray(TM).
|
|
|
|
|
|
The above figures are
reprinted
by permission from Elsevier:
J Mol Biol
(2001,
310,
875-884)
copyright 2001.
|
|
|
|
|
|
|
