Eukaryotic initiation factor 4A-1 (eIF4A1) is an ATP-dependent RNA helicase that unwinds 5'-UTR mRNA secondary structures to facilitate cap-dependent translation initiation. Rocaglates, a class of natural products typified by rocaglamide A (RocA), possess antineoplastic and anti-infectious activity mediated by their interaction with eIF4A1. Rocaglates inhibit cap-dependent translation initiation by "clamping" eIF4A1 onto polypurine RNA, which impedes ribosome scanning. A novel class of rocaglate derivatives, amidino-rocaglates (ADRs) which feature an amidine ring fused to the rocaglate core, is particularly effective at promoting eIF4A1-RNA-clamping compared to other rocaglate congeners. Herein, we present the X-ray crystal structure of an ADR in complex with eIF4A1, the nonhydrolyzable ATP ground-state mimic adenylyl-imidodiphosphate (AMPPNP), and poly r(AG)