 |
PDBsum entry 3k72
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cell adhesion
|
PDB id
|
|
|
|
3k72
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Structure of an integrin with an alphai domain, Complement receptor type 4.
|
|
|
Authors
|
|
C.Xie,
J.Zhu,
X.Chen,
L.Mi,
N.Nishida,
T.A.Springer.
|
|
|
Ref.
|
|
Embo J, 2010,
29,
666-679.
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Abstract
|
|
|
We report the structure of an integrin with an alphaI domain, alpha(X)beta(2),
the complement receptor type 4. It was earlier expected that a fixed orientation
between the alphaI domain and the beta-propeller domain in which it is inserted
would be required for allosteric signal transmission. However, the alphaI domain
is highly flexible, enabling two betaI domain conformational states to couple to
three alphaI domain states, and greater accessibility for ligand recognition.
Although alpha(X)beta(2) is bent similarly to integrins that lack alphaI
domains, the terminal domains of the alpha- and beta-legs, calf-2 and beta-tail,
are oriented differently than in alphaI-less integrins. Linkers extending to the
transmembrane domains are unstructured. Previous mutations in the beta(2)-tail
domain support the importance of extension, rather than a deadbolt, in integrin
activation. The locations of further activating mutations and antibody epitopes
show the critical role of extension, and conversion from the closed to the open
headpiece conformation, in integrin activation. Differences among 10 molecules
in crystal lattices provide unprecedented information on interdomain flexibility
important for modelling integrin extension and activation.
|
|
|
|
|
|
|
