Extended Data Fig. 9: RBFA conformational change between preSSU-2 and preSSU-3, and structures of preSSU-3a,b,c states.
From: Mechanism of mitoribosomal small subunit biogenesis and preinitiation
a, METTL15 from preSSU3 is superimposed with RBFA-in from preSSU-2 showing their clash. b, Comparison between RBFA-in, RBFA-out, AlphaFold2 prediction shows that the predicted conformation is different from the known structure of RBFA-in. c, RBFA:METTL15 complex prediction with AlphaFold2 shows the interaction through the RBFA CTE helix found in the structure. d, In preSSU-3a, METTL15 has tight interactions with the rRNA and the mito-specific insertion forms an α-helix. The tip of h24 is shifted, which opens the space between h24 and h44, and shifts the entire SSU platform. In preSSU-3b, the mito-specific insertion is mostly disordered and METTL15 has a looser contact to h24, resulting in the mature conformation of h24, whereas h23 is extended and detached from the tip of h24. In preSSU-3c, the METTL15:rRNA interactions are the same in preSSU-2b and the rRNA is completely folded. e, Interactions between METTL15 and rRNA. The mito-specific insertion of METTL15 interacts with h23, h24, and h45, mainly through Asn343, Leu344 (mainchain), Val346 (mainchain) Arg347, and Asn349.
