A translation factor that gates the progression of the 70S ribosomal initiation complex (IC, containing tRNA(fMet) in the P-site) into the translation elongation cycle by using a mechanism sensitive to the ATP/ADP ratio. Binds to the 70S ribosome E-site where it modulates the state of the translating ribosome during subunit translocation. ATP hydrolysis probably frees it from the ribosome, which can enter the elongation phase. ATP + H2O = ADP + H(+) + phosphate Monomer. Probably contacts ribosomal proteins L1, L5, L33 and S7, the 16S and 23S rRNA and the P-site containing tRNA(fMet). Associates with ribosomes and polysomes. The arm domain is inserted in the first ABC transporter domain. Probably contacts ribosomal protein L1. The P-site tRNA interaction motif (PtIM domain) probably interacts with the P-site tRNA(fMet) as well as the 23S rRNA. Belongs to the ABC transporter superfamily. ABCF family. Translational throttle EttA subfamily.