4wjs
Crystal structure of Rsa4 from Chaetomium thermophilum
Structural highlights
FunctionNLE1_CHATD Involved in ribosome biogenesis. Required for processing and efficient intra-nuclear transport of pre-60S ribosomal subunits. Interacts with the AAA-ATPase Midasin, which is essential for the ATP-dependent dissociation of a group of nonribosomal factors from the pre-60S particle.[UniProtKB:P25382] Publication Abstract from PubMedEukaryotic ribosome biogenesis involves approximately 200 assembly factors, but how these contribute to ribosome maturation is poorly understood. Here, we identify a network of factors on the nascent 60S subunit that actively remodels preribosome structure. At its hub is Rsa4, a direct substrate of the force-generating ATPase Rea1. We show that Rsa4 is connected to the central protuberance by binding to Rpl5 and to ribosomal RNA (rRNA) helix 89 of the nascent peptidyl transferase center (PTC) through Nsa2. Importantly, Nsa2 binds to helix 89 before relocation of helix 89 to the PTC. Structure-based mutations of these factors reveal the functional importance of their interactions for ribosome assembly. Thus, Rsa4 is held tightly in the preribosome and can serve as a "distribution box," transmitting remodeling energy from Rea1 into the developing ribosome. We suggest that a relay-like factor network coupled to a mechano-enzyme is strategically positioned to relocate rRNA elements during ribosome maturation. A network of assembly factors is involved in remodeling rRNA elements during preribosome maturation.,Bassler J, Paternoga H, Holdermann I, Thoms M, Granneman S, Barrio-Garcia C, Nyarko A, Stier G, Clark SA, Schraivogel D, Kallas M, Beckmann R, Tollervey D, Barbar E, Sinning I, Hurt E J Cell Biol. 2014 Nov 24;207(4):481-98. doi: 10.1083/jcb.201408111. Epub 2014 Nov, 17. PMID:25404745[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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