Table 2. The structural analysis of atomic models of the translocational ribosome.

Structure	R1	The angle of head	The width of the P/E-gate	The angle of ratchet	The state of tRNA	PDB code (EMD code) resolution
TIPRE(2tRNAs)	41.8 Å	−9.8°	23.9 Å	9.0°	P/E	3J5X/3J5W
					A/P*	(EMD-5800).
						7.6 Å [16].
TIPRE(Fus)	32.2 Å	−6.5°	25.4 Å	6.8°	P/E	2XSY/2XTG
						(EMD-1798)
						7.8 Å [15]
TIPRE(GDPCP1)	27.9 Å	−5.2°	24.2 Å	6.8°	P/E	4BTC/4BTD
						2.95 Å [8]
TIPRE(GDPCP2)	27.9 Å	−5.5°	24.0 Å	6.8°	P/E	4JUW/4JUX
						2.86 Å [9]
TIPOST(2tRNAs)	33.1 Å	−22.8°	31.2 Å	5.7°	ap/P1	3J5N/3J5O
					pe/E	(EMD-5775)
						6.8 Å [17]
TIPOST(Fus1)	37.8 Å	−17.5°	32.8 Å	6.6°	pe/E	2XUY/2XUX
						(EMD-1799)
						7.6 Å [15]
TIPOST(Fus2)	20.0 Å	−17.7°	30.3 Å	3.4°	pe*/E2	4KD8/4KD9
						3.5 Å [11]
Initial	0.0 Å	−1.6°	24.1 Å	0.0°	E/E	2WRI/2WRJ
					P/P	3.6 Å [10]

¹In TI^POST(2tRNAs), two tRNAs are present in ap/P and pe/E hybrid states, where the lowercase and uppercase letters indicate tRNA contacts on the small and large subunit, respectively, in the following order: 30S head (a-site or p-site), 30S body/platform (p-site or e-site) and 50S subunit (P-site or E-site).

²In TI^POST(Fus2), a single tRNA is present in a pe*/E hybrid state, where e* in pe*/E means that the anticodon stem-loop (ASL) of the tRNA lies between the p- and e-sites of the 30S body/platform.

TI^PRE(2tRNAs) consists of the ribosome, two tRNAs, mRNA, EF-G, GDP and viomycin. Each TI^PRE(Fus), TI^POST(Fus1) and TI^POST(Fus2) consists of the ribosome, a single tRNA, mRNA, EF-G and fusidic acid (Fus). Each TI^PRE(GDPCP1) and TI^PRE(GDPCP2) consists of the ribosome, a single tRNA, mRNA, EF-G, GDPCP. TI^POST(2tRNAs) consists of the ribosome, two tRNAs, mRNA, EF-G, GDP and Fus.

For 3J5X/3J5W and 3J5N/3J5O (E. coli ribosome), their superpositions on 2WRI/2WRI (Thermus thermophiles ribosome) were carried out using Chimera software's MatchMaker tool [73].