Anno2015
AutoriMastrangelo E.; Vachette P.; Cossu F.; Malvezzi F.; Bolognesi M.; Milani M.
AbstractSmac-DIABLO in its mature form (20.8 kDa) binds to baculoviral IAP repeat (BIR) domains of inhibitor of apoptosis proteins (IAPs) releasing their inhibitory effects on caspases, thus promoting cell death. Despite its apparent molecular mass (~100 kDa), Smac-DIABLO was held to be a dimer in solution, simultaneously targeting two distinct BIR domains. We report an extensive biophysical characterization of the protein alone and in complex with the X-linked IAP (XIAP)-BIR2-BIR3 domains. Our data show that Smac-DIABLO adopts a tetrameric assembly in solution and that the tetramer is able to bind two BIR2-BIR3 pairs of domains. Our small-angle x-ray scattering-based tetrameric model of Smac-DIABLO/BIR2-BIR3 highlights some conformational freedom of the complex that may be related to optimization of IAPs binding.
RivistaBiophysical Journal (print)
ISSN0006-3495
Impact factor0
Volume108
Pagina inizio714
Pagina fine723
Autori IBFEloise MASTRANGELO, Mario MILANI
Linee di Ricerca IBFMD.P01.005.001
Sedi IBFIBF.MI