第1354回生物科学セミナー
Structural studies of mitochondrial ribosome
伊藤弓弦, Ph.D.（Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University）
2020年11月30日(月) 16:00-17:00 Zoomによるweb講義
Mitochondrial ribosomes (mitoribosomes) are tethered to the mitochondrial inner membrane to facilitate the co-translational membrane insertion of the synthesized proteins. We report cryo-electron microscopy structures of human mitoribosomes with nascent polypeptide, bound to the insertase OXA1L through three distinct contact sites. OXA1L binding is correlated with a series of conformational changes in the mitoribosomal large subunit that catalyze the delivery of newly synthesized polypeptides. The mechanism relies on the folding of mL45 inside the exit tunnel, forming two specific constriction sites that prevent the helix formation of the nascent chain. A gap is formed between the exit and the membrane, making the newly synthesized proteins accessible. Other unpublished structural data of human mitoribosome will be also presented.
担当：東京大学大学院理学系研究科・生物科学専攻・濡木理
