 |
PDBsum entry 1is4
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Sugar binding protein
|
PDB id
|
|
|
|
1is4
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
|
|
* Residue conservation analysis
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Crystal structure of a conger eel galectin (congerin ii) at 1.45a resolution: implication for the accelerated evolution of a new ligand-Binding site following gene duplication.
|
|
|
Authors
|
|
T.Shirai,
Y.Matsui,
C.Shionyu-Mitsuyama,
T.Yamane,
H.Kamiya,
C.Ishii,
T.Ogawa,
K.Muramoto.
|
|
|
Ref.
|
|
J Mol Biol, 2002,
321,
879-889.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
The crystal structure of congerin II, a galectin family lectin from conger eel,
was determined at 1.45A resolution. The previously determined structure of its
isoform, congerin I, had revealed a fold evolution via strand swap; however, the
structure of congerin II described here resembles other prototype galectins. A
comparison of the two congerin genes with that of several other galectins
suggests acceralated evolution of both congerin genes following gene
duplication. The presence of a Mes (2-[N-morpholino]ethanesulfonic acid)
molecule near the carbohydrate-binding site in the crystal structure points to
the possibility of an additional binding site in congerin II. The binding site
consists of a group of residues that had been replaced following gene
duplication suggesting that the binding site was built under selective pressure.
Congerin II may be a protein specialized for biological defense with an affinity
for target carbohydrates on parasites' cell surface.
|
|
|
|
|
|
|
|
Figure 2.
Figure 2. (a) The carbohydrate-binding site of congerin II.
The side-chains that bind the lactose or Mes molecules are shown
in blue. The hydrogen bonds between protein and ligand are shown
in yellow. The water molecule mediating hydrogen bonding is
represented as a red sphere. Omit electron density map around
the ligand molecules is superposed as purple network. The map
was phased by the final model without the ligand atoms, and
contoured at 3.0s level. (b) Comparison between the binding
sites of congerin II in ternary complex (blue) and in apo form
(orange). The spheres are water molecules in the apo form;
hydrogen bonds are shown in yellow.
|
|
Figure 7.
Figure 7. A comparison of carbohydrate-binding sites of
congerin II (blue), congerin I (orange) and bovine galectin-1
(gray). The residues are labeled as congerin II amino acid and
residue number: corresponding amino acid of congerin I:
corresponding amino acid of galectin-1.
|
|
|
|
|
|
The above figures are
reprinted
by permission from Elsevier:
J Mol Biol
(2002,
321,
879-889)
copyright 2002.
|
|
|
|
|
|
|
