3.A.1.120.8
 ABC protein of 558 aas and 0 TMSs, Rv2477c.  It is 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. It is an ABC-F subfamily protein, members of which are implicated in diverse cellular processes such as translation, antibiotic resistance, cell growth and nutrient sensing. Daniel et al. 2018 showed that Rv2477c displays strong ATPase activity (Vmax = 45 nmol/mg/min; Km = 90 muM) that is sensitive to orthovanadate. The ATPase activity was maximal in the presence of Mn²⁺ at pH 5.2. The protein hydrolyzed GTP, TTP and CTPas well as ATP but at lower rates. Glutamate to glutamine substitutions of amino acid residues 185 and 468 in the two Walker B motifs severely inhibited its ATPase activity. The antibiotics, tetracycline and erythromycin, which target protein translation, were able to inhibit the ATPase activity. Daniel et al. 2018 postulated that Rv2477c is involved in mycobacterial protein translation and in resistance to tetracyclines and macrolides.