A network of assembly factors is involved in remodeling rRNA elements during preribosome maturation

作者：Bassler Jochen; Paternoga Helge; Holdermann Iris; Thoms Matthias; Granneman Sander; Barrio Garcia Clara; Nyarko Afua; Stier Gunter; Clark Sarah A; Schraivogel Daniel; Kallas Martina; Beckmann Roland; Tollervey David; Barbar Elisar; Sinning Irmi; Hurt Ed^*

来源：The Journal of Cell Biology, 2014, 207(4): 481-498.

DOI：10.1083/jcb.201408111

Eukaryotic ribosome biogenesis involves similar to 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 Real. We show that Rsa4 is connected to the central protuberance by binding to Rp15 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 %26quot;distribution box,%26quot; transmitting remodeling energy from Real 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.

• 出版日期2014-11-24