 |
PDBsum entry 4mo7
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Transcription
|
PDB id
|
|
|
|
4mo7
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Pfit is a structurally novel crohn'S disease-Associated superantigen.
|
|
|
Authors
|
|
L.Liu,
H.Chen,
M.B.Brecher,
Z.Li,
B.Wei,
B.Nandi,
J.Zhang,
H.Ling,
G.Winslow,
J.Braun,
H.Li.
|
|
|
Ref.
|
|
Plos Pathog, 2013,
9,
e1003837.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
T cell responses to enteric bacteria are important in inflammatory bowel
disease. I2, encoded by the pfiT gene of Pseudomonas fluorescens, is a T-cell
superantigen associated with human Crohn's disease. Here we report the crystal
structure of pfiT at 1.7Å resolution and provide a functional analysis of the
interaction of pfiT and its homolog, PA2885, with human class II MHC. Both pfiT
and PA2885 bound to mammalian cells and stimulated the proliferation of human
lymphocytes. This binding was greatly inhibited by anti-class II MHC HLA-DR
antibodies, and to a lesser extent, by anti HLA-DQ and DP antibodies, indicating
that the binding was class II MHC-specific. GST-pfiT efficiently precipitated
both endogenous and in vitro purified recombinant HLA-DR1 molecules, indicating
that pfiT directly interacted with HLA-DR1. Competition studies revealed that
pfiT and the superantigen Mycoplasma arthritidis mitogen (MAM) competed for
binding to HLA-DR, indicating that their binding sites overlap. Structural
analyses established that pfiT belongs to the TetR-family of DNA-binding
transcription regulators. The distinct structure of pfiT indicates that it
represents a new family of T cell superantigens.
|
|
|
|
|
|
|
