イーストミトコンドリアリボソームの構造

Nirupa Desai¹, Alan Brown¹, Alexey Amunts^1,2

¹MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.

Science (New York, N.Y.)

|February 4, 2017

まとめ

研究者は酵母ミトリボソームを視覚化し独特の構造と成分を明らかにしましたこの研究は,ミトコンドリア変換の特異性とその進化的分岐を明らかにしています.

科学分野:

分子生物学
構造生物学
遺伝学

背景:

ミトコンドリアには遺伝子発現のためのユニークなリボソーム (ミトリボソーム) がある.
ミトコンドリアの機能の鍵となるのはミトコンドリアの構造を理解することです

研究の目的:

イーストミトリボソムの高解像度構造を決定する.
ミトコンドリアトランスレーションの進化的特異性を調査する

主な方法:

電子冷凍顕微鏡 (cryo-EM) が使用された.
75組分の酵母ミトリボソームの構造は3. 3アングストームに解消された.

主要な成果:

小型のサブユニットは15SリボソームRNA (rRNA) と34のタンパク質,14の新規タンパク質で構成されています.
酵母菌のミトリボソームは,独特のrRNAとタンパク質要素を含む哺乳類の同類と異なる構造を示しています.
mRNAチャネルの出口にあるトランスレーションアクティベータのプラットフォームは,種特有の調節を示唆する.

結論:

決定された構造は酵母ミトリボソームの組成と構造に関する原子レベルの洞察を提供します.
発見は,種間のミトコンドリア変換の進化的適応と専門性を強調しています.
この研究は,ミトコンドリア機能障害に関連した病気を理解するための基盤を提供します.

さらに関連する動画

08:55

Assessment of Submitochondrial Protein Localization in Budding Yeast Saccharomyces cerevisiae

Published on: July 19, 2021

3.4K

14:44

Isolation of mRNAs Associated with Yeast Mitochondria to Study Mechanisms of Localized Translation

Published on: March 14, 2014

13.4K

関連する概念動画

01:27

Ribosomes

79.6K

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome...

Ribosomes

Porin Insertion in the Outer Mitochondrial Membrane

5.0K

Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...

5.0K

01:21

Structure of Porins

4.1K

Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel...

4.1K

01:39

Mitochondrial Protein Sorting

5.9K

Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death. Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...

5.9K

02:53

Ribosomal RNA Synthesis

15.0K

Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...