Structural and functional analysis of phosphorylation-specific binders of the kinase ERK from designed ankyrin repeat protein libraries.

ABSTRACT: We have selected designed ankyrin repeat proteins (DARPins) from a synthetic library by using ribosome display that selectively bind to the mitogen-activated protein kinase ERK2 (extracellular signal-regulated kinase 2) in either its nonphosphorylated (inactive) or doubly phosphorylated (active) form. They do not bind to other kinases tested. Crystal structures of complexes with two DARPins, each specific for one of the kinase forms, were obtained. The two DARPins bind to essentially the same region of the kinase, but recognize the conformational change within the activation loop and an adjacent area, which is the key structural difference that occurs upon activation. Whereas the rigid phosphorylated activation loop remains in the same form when bound by the DARPin, the more mobile unphosp

SUBMITTER: Kummer L 

PROVIDER: S-EPMC3427131 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature