 |
PDBsum entry 1wmz
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Sugar binding protein
|
PDB id
|
|
|
|
1wmz
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
* Residue conservation analysis
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Characteristic recognition of n-Acetylgalactosamine by an invertebrate c-Type lectin, Cel-I, Revealed by X-Ray crystallographic analysis.
|
|
|
Authors
|
|
H.Sugawara,
M.Kusunoki,
G.Kurisu,
T.Fujimoto,
H.Aoyagi,
T.Hatakeyama.
|
|
|
Ref.
|
|
J Biol Chem, 2004,
279,
45219-45225.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
CEL-I is a C-type lectin, purified from the sea cucumber Cucumaria echinata,
that shows a high specificity for N-acetylgalactosamine (GalNAc). We determined
the crystal structures of CEL-I and its complex with GalNAc at 2.0 and 1.7 A
resolution, respectively. CEL-I forms a disulfide-linked homodimer and contains
two intramolecular disulfide bonds, although it lacks one intramolecular
disulfide bond that is widely conserved among various C-type carbohydrate
recognition domains (CRDs). Although the sequence similarity of CEL-I with other
C-type CRDs is low, the overall folding of CEL-I was quite similar to those of
other C-type CRDs. The structure of the complex with GalNAc revealed that the
basic recognition mode of GalNAc was very similar to that for the GalNAc-binding
mutant of the mannose-binding protein. However, the acetamido group of GalNAc
appeared to be recognized more strongly by the combination of hydrogen bonds to
Arg115 and van der Waals interaction with Gln70. Mutational analyses, in which
Gln70 and/or Arg115 were replaced by alanine, confirmed that these residues
contributed to GalNAc recognition in a cooperative manner.
|
|
|
|
|
|
|
|
Figure 1.
FIG. 1. Stereo view of the ribbon model of CEL-I (protomer
A). The  -helices,  -strands,
loops, and intramolecular disulfide bonds are shown in purple,
blue, gray, and green, respectively. Bound calcium ions are
shown by cyan spheres. Secondary structures were determined by
the program PROMOTIF (45). Fig. 1 was drawn by the program
MOLSCRIPT (46) and rendered by the program Raster3D (47).
|
|
Figure 6.
FIG. 6. Comparison of the carbohydrate-binding modes of
CEL-I and the GalNAc-binding mutant of MBP. A, electron density
map around the GalNAc-binding site of CEL-I (protomer 1A). A
2F[obs] - F[calc] omit map is drawn at the 1.5  level.
Carbon, oxygen, nitrogen, and calcium atoms are shown in green,
red, blue, and purple, respectively. B, overlapped structures of
CEL-I (protomer 1A) and the mutant MBP around the bound GalNAc.
C, overlapped structures of CEL-I (protomer 1A) and the mutant
MBP around the acetamido group. GalNAc, the calcium ion, and its
binding residues in CEL-I and the MBP mutant are superimposed.
Carbon, calcium atoms, and residue numbers of CEL-I and the
mutant MBP are shown in green and yellow, respectively. Hydrogen
and coordination bonds are indicated by dots. The GalNAc-binding
site structure of protomer 2A is similar to this site. Fig. 6
was drawn by the program PyMOL (49).
|
|
|
|
|
|
The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2004,
279,
45219-45225)
copyright 2004.
|
|
|
Secondary reference #1
|
|
|
Title
|
|
Crystallization and preliminary crystallographic study of an invertebrate c-Type lectin, Cel-I, From the marine invertebrate cucumaria echinata.
|
|
|
Authors
|
|
T.Hatakeyama,
N.Matsuo,
H.Aoyagi,
H.Sugawara,
T.Uchida,
G.Kurisu,
M.Kusunoki.
|
|
|
Ref.
|
|
Acta Crystallogr D Biol Crystallogr, 2002,
58,
143-144.
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
|
|
|
|
