@article {689086,
	title = {Leukocyte integrin αLβ2 headpiece structures: The αI domain, the pocket for the internal ligand, and concerted movements of its loops},
	journal = {Proc Natl Acad Sci U S A.},
	year = {2016},
	month = {2 March, 2016},
	abstract = {High-resolution crystal structures of the headpiece of lymphocyte function-associated antigen-1 (integrin αLβ2) reveal how the αI domain interacts with its platform formed by the α-subunit β-propeller and β-subunit βI domains. The αLβ2\&nbsp;structures compared with αXβ2\&nbsp;structures show that the αI domain, tethered through its N-linker and a disulfide to a stable β-ribbon pillar near the center of the platform, can undergo remarkable pivoting and tilting motions that appear buffered by N-glycan decorations that differ between αL\&nbsp;and αX\&nbsp;subunits. Rerefined β2\&nbsp;integrin structures reveal details including pyroglutamic acid at the β2\&nbsp;N terminus and bending within the EGF1 domain. Allostery is relayed to the αI domain by an internal ligand that binds to a pocket at the interface between the β-propeller and βI domains. Marked differences between the αL\&nbsp;and αX\&nbsp;subunit β-propeller domains concentrate near the binding pocket and αI domain interfaces. Remarkably, movement in allostery in the βI domain of specificity determining loop 1 (SDL1) causes concerted movement of SDL2 and thereby tightens the binding pocket for the internal ligand.},
	author = {Sen, Mehmet and Springer, T.A.}
}
