Bettina Bradatsch / Christoph Leidig / Sander Granneman / Marén Gnädig / David Tollervey / Bettina Böttcher / Roland Beckmann / Ed Hurt /
PubMed 要旨
Preribosomal particles evolve in the nucleus through transient interaction with biogenesis factors before export to the cytoplasm. Here, we report the architecture of the late pre-60S particle, ...Preribosomal particles evolve in the nucleus through transient interaction with biogenesis factors before export to the cytoplasm. Here, we report the architecture of the late pre-60S particle, purified from Saccharomyces cerevisiae, through Arx1, a nuclear export factor with structural homology to methionine aminopeptidases, or its binding partner Alb1. Cryo-EM reconstruction of the Arx1 particle at 11.9-Å resolution reveals regions of extra density on the pre-60S particle attributed to associated biogenesis factors, confirming the immature state of the nascent subunit. One of these densities could be unambiguously assigned to Arx1. Immunoelectron microscopy and UV cross-linking localize Arx1 close to the ribosomal exit tunnel, in direct contact with ES27, a highly dynamic eukaryotic rRNA expansion segment. The binding of Arx1 at the exit tunnel may position this export factor to prevent premature recruitment of ribosome-associated factors active during translation.
EMDB-5513, PDB-3j2i: Structure of late pre-60S ribosomal subunits with nuclear export factor Arx1 bound at the peptide exit tunnel 手法: EM (単粒子) / 解像度: 11.9 Å
由来
saccharomyces cerevisiae (パン酵母)
homo sapiens (ヒト)
キーワード
RIBOSOMAL PROTEIN / SIGNALING PROTEIN / ribosome / pre-ribosome / cryo-EM