 |
PDBsum entry 3th0
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Viral protein
|
PDB id
|
|
|
|
3th0
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
An essential serotype recognition pocket on phage p22 tailspike protein forces salmonella enterica serovar paratyphi a o-Antigen fragments to bind as nonsolution conformers.
|
|
|
Authors
|
|
D.Andres,
U.Gohlke,
N.K.Broeker,
S.Schulze,
W.Rabsch,
U.Heinemann,
S.Barbirz,
R.Seckler.
|
|
|
Ref.
|
|
Glycobiology, 2013,
23,
486-494.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Abstract
|
|
|
Bacteriophage P22 recognizes O-antigen polysaccharides of Salmonella enterica
subsp. enterica (S.) with its tailspike protein (TSP). In the serovars S.
Typhimurium, S. Enteritidis, and S. Paratyphi A, the tetrasaccharide repeat
units of the respective O-antigens consist of an identical main chain
trisaccharide but different 3,6-dideoxyhexose substituents. Here, the epimers
abequose, tyvelose and paratose determine the specific serotype. P22 TSP
recognizes O-antigen octasaccharides in an extended binding site with a single
3,6-dideoxyhexose binding pocket. We have isolated S. Paratyphi A
octasaccharides which were not available previously and determined the crystal
structure of their complex with P22 TSP. We discuss our data together with
crystal structures of complexes with S. Typhimurium and S. Enteritidis
octasaccharides determined earlier. Isothermal titration calorimetry showed that
S. Paratyphi A octasaccharide binds P22 TSP less tightly, with a difference in
binding free energy of ∼7 kJ mol(-1) at 20°C compared with S. Typhimurium and
S. Enteritidis octasaccharides. Individual protein-carbohydrate contacts were
probed by amino acid replacements showing that the dideoxyhexose pocket
contributes to binding of all three serotypes. However, S. Paratyphi A
octasaccharides bind in a conformation with an energetically unfavorable ϕ/ψ
glycosidic bond angle combination. In contrast, octasaccharides from the other
serotypes bind as solution-like conformers. Two water molecules are conserved in
all P22 TSP complexes with octasaccharides of different serotypes. They line the
dideoxyhexose binding pocket and force the S. Paratyphi A octasaccharides to
bind as nonsolution conformers. This emphasizes the role of solvent as part of
carbohydrate binding sites.
|
|
|
Secondary reference #1
|
|
|
Title
|
|
Crystal structure of p22 tailspike protein: interdigitated subunits in a thermostable trimer.
|
|
|
Authors
|
|
S.Steinbacher,
R.Seckler,
S.Miller,
B.Steipe,
R.Huber,
P.Reinemer.
|
|
|
Ref.
|
|
Science, 1994,
265,
383-386.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Secondary reference #2
|
|
|
Title
|
|
Crystal structure of phage p22 tailspike protein complexed with salmonella sp. O-Antigen receptors.
|
|
|
Authors
|
|
S.Steinbacher,
U.Baxa,
S.Miller,
A.Weintraub,
R.Seckler,
R.Huber.
|
|
|
Ref.
|
|
Proc Natl Acad Sci U S A, 1996,
93,
10584-10588.
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
|
|
|
|
