Mpp10 represents a platform for the interaction of multiple factors within the 90S pre-ribosome

Abstract

In eukaryotes, ribosome assembly is a highly complex process that involves more than 200 assembly factors that ensure the folding, modification and processing of the different rRNA species as well as the timely association of ribosomal proteins. One of these factors, Mpp10 associates with Imp3 and Imp4 to form a complex that is essential for the normal production of the 18S rRNA. Here we report the crystal structure of a complex between Imp4 and a short helical element of Mpp10 to a resolution of 1.88 Å. Furthermore, we extend the interaction network of Mpp10 and characterize two novel interactions. Mpp10 is able to bind the ribosome biogenesis factor Utp3/Sas10 through two conserved motifs in its N-terminal region. In addition, Mpp10 interacts with the ribosomal protein S5/uS7 using a short stretch within an acidic loop region. Thus, our findings reveal that Mpp10 provides a platform for the simultaneous interaction with multiple proteins in the 90S pre-ribosome.

Cryo-EM structure of an early precursor of large ribosomal subunit reveals a half-assembled intermediate

“…Brx1 adopts an α/β fold with pseudo 2-fold symmetry (Fig. 4A), similar to other Brix domain proteins (Ng et al, 2005; Asano et al, 2015; Kharde et al, 2015; Madru et al, 2015; Sa-Moura et al, 2017). The structural core of Brx1 is composed of two curved β-sheets that form a half-open β-barrel sandwiching two α-helices (α1 and α3).…”

Interdependent action of KH domain proteins Krr1 and Dim2 drive the 40S platform assembly

“…no. : 06-549, 1:3000), anti-Rps5 (Santa Cruz Biotechnology, C-200, 1:500) (the antibody was tested in our laboratory for specificity 61 ), anti-Rpl5 62 (1:500), anti-Rps8 63 (1:5000), anti-Nob1 27 (1:2000), anti-Rps26/Tsr2 43 (1:2000), anti-Rps14/Fap7 (1:2000) 42 and secondary antibodies goat anti-mouse (Bio-Rad -170-6516, 1:3000), donkey anti-goat (Dianova, 705-075-147), goat anti-rabbit (Bio-Rad -170-6515, 1:2000). Validation of commercial primary antibodies is provided on the manufacturers’ website.…”

Cryo-EM structure of an early precursor of large ribosomal subunit reveals a half assembled intermediate

“…We determined a crystal structure of Brx1 (residues 26-255) in complex with Ebp2 (residues 195-293) at 2.3 Å resolution with de novo phasing (Table S3). Brx1 adopts an α/β fold with pseudo 2-fold symmetry ( Figure 4A), like other Brix domain proteins (38)(39)(40)(41)(42). The structural core of Brx1 is composed of two curved β-sheets that from a half-open β-barrel sandwiching two α-helices (α1 and α3).…”