TY - JOUR T1 - Ribosome recycling is coordinated by processive events in two asymmetric ATP sites of ABCE1 JF - Life Science Alliance JO - Life Sci. Alliance DO - 10.26508/lsa.201800095 VL - 1 IS - 3 SP - e201800095 AU - Elina Nürenberg-Goloub AU - Holger Heinemann AU - Milan Gerovac AU - Robert Tampé Y1 - 2018/06/01 UR - https://www.life-science-alliance.org/content/1/3/e201800095.abstract N2 - Ribosome recycling orchestrated by ABCE1 is a fundamental process in protein translation and mRNA surveillance, connecting termination with initiation. Beyond the plenitude of well-studied translational GTPases, ABCE1 is the only essential factor energized by ATP, delivering the energy for ribosome splitting via two nucleotide-binding sites by a yet unknown mechanism. Here, we define how allosterically coupled ATP binding and hydrolysis events in ABCE1 empower ribosome recycling. ATP occlusion in the low-turnover control site II promotes formation of the pre-splitting complex and facilitates ATP engagement in the high-turnover site I, which in turn drives the structural reorganization required for ribosome splitting. ATP hydrolysis and ensuing release of ABCE1 from the small subunit terminate the post-splitting complex. Thus, ABCE1 runs through an allosterically coupled cycle of closure and opening at both sites, consistent with a processive clamp model. This study delineates the inner mechanics of ABCE1 and reveals why various ABCE1 mutants lead to defects in cell homeostasis, growth, and differentiation. ER -