Fig. 3.

Average smFRET data characterizing 30S head rotations (S13-L33 FRET), 30S subunit rotations (S6-L9 FRET), mRNA movement (Alx405 fluorescence) and tRNA dissociation (tRNA-L33 FRET). (a) Time courses of single smFRET data with the time when the smFRET changes value being replaced with the average time. (b) Time courses of ensemble smFRET data (with N$\ge$ 10000) or ensemble kinetic data calculated with differential equations (11)–(21). Line 1 (blue broken line) represents the average time when EF-G.GTP binds to the ribosome, line 4 represents the average time when the reverse 30S subunit, the reverse 30S head and the mRNA movement take place, and line 5 represents the average time when the deacylated tRNA dissociates from the E/E site of the ribosome. Line 2 in (b) represents the time when the ensemble FRET data characterizing 30S head rotations begin to increase, with the decrease of FRET data corresponding to the forward 30S head rotation while the increase of FRET data corresponding to the reverse 30S head rotation. Line 3 in (b) represents the time when the ensemble FRET data characterizing 30S subunit rotations begin to increase, with the decrease of FRET data corresponding to the forward 30S subunit rotation while the increase of FRET data corresponding to the reverse 30S subunit rotation.