Jove
Visualize
お問い合わせ
JoVE
x logofacebook logolinkedin logoyoutube logo
JoVEについて
概要リーダーシップブログJoVEヘルプセンター
著者向け
出版プロセス編集委員会範囲と方針査読よくある質問投稿
図書館員向け
推薦の声購読アクセスリソース図書館諮問委員会よくある質問
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experimentsアーカイブ
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教員リソースセンター教員サイト
利用規約
プライバシーポリシー
ポリシー

関連する概念動画

Radical Reactivity: Electrophilic Radicals01:02

Radical Reactivity: Electrophilic Radicals

Radicals adjacent to electron‐withdrawing groups are called electrophilic radicals. These radicals readily react with nucleophilic alkenes. For example, the malonate radical, in which the radical center is flanked by two electron‐withdrawing groups, reacts readily with butyl vinyl ether, which consists of an electron‐donating oxygen substituent. The reaction between electrophilic malonate radical and nucleophilic vinyl ether is favored because the radical has a low‐energy SOMO, which interacts...
Radical Reactivity: Overview01:11

Radical Reactivity: Overview

Radicals, the highly reactive species, gain stability by undergoing three different reactions. The first reaction involves a radical-radical coupling, in which a radical combines with another radical, forming a spin‐paired molecule. The second reaction is between a radical and a spin‐paired molecule, generating a new radical and a new spin‐paired molecule. The third reaction is radical decomposition in a unimolecular reaction, forming a new radical and a spin‐paired molecule. These three...
Radical Reactivity: Nucleophilic Radicals01:16

Radical Reactivity: Nucleophilic Radicals

Radicals adjacent to electron-donating groups are called nucleophilic radicals. These radicals readily react with electrophilic alkenes. The SOMO–LUMO interactions are the driving force for the reaction, where the high-energy SOMO of the electron-rich, nucleophilic radicals interacts with the low-energy LUMO of the electron-deficient, electrophilic alkenes. Such SOMO–LUMO interactions are the basis of reactive radical traps, affecting the selectivity in radical reactions. For instance, consider...
Radical Reactivity: Steric Effects01:10

Radical Reactivity: Steric Effects

The presence of electron-donating, electron-withdrawing, or conjugating groups adjacent to a radical center, imparts electronic stabilization to the radicals. Examples of such electronically-stabilized radicals are triphenylmethyl, tetramethylpiperidine‐N‐oxide, and 2,2‐diphenyl‐1‐picrylhydrazyl. These radicals are remarkably stable and are known as persistent radicals. Some of the persistent radicals can even be isolated and purified.
Along with electronic factors, steric factors also account...
Radical Formation: Addition00:47

Radical Formation: Addition

Radicals can be formed by adding a radical to a spin-paired molecule. This is typically observed with unsaturated species, where the addition of a radical across the π bond leads to the production of a new radical by dissolving the π bond. For example, the addition of a Br radical to an alkene yields a carbon-centered radical.
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an unpaired...
Phase II Reactions: Methylation Reactions01:17

Phase II Reactions: Methylation Reactions

Methylation is a phase II biotransformation process involving the attachment of a methyl group to a substrate. Enzymes known as methyltransferases orchestrate this reaction.
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...

こちらも読む

関連記事

共著者、ジャーナル、引用グラフによってこの研究に関連する記事。

並び替え
Same author

Differentiating 5-thiooxazoles from oxazolone-coupled thioamides in RiPP natural products.

bioRxiv : the preprint server for biology·2026
Same author

Amino Acids in the RSSY Motif of Lipoyl Synthase Control Substrate Binding and Reactivity.

bioRxiv : the preprint server for biology·2026
Same author

Structural and Spectroscopic Basis for Catalysis by a Class C Radical <i>S</i>-Adenosylmethionine Methylase Involved in Nosiheptide/Nocathiacin Biosynthesis.

Journal of the American Chemical Society·2026
Same author

A redox- and proton-coupled inner membrane transporter mediates copper import to the bacterial cytoplasm.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

Bis-hydroxylation of Homocitrulline Catalyzed by a Multinuclear Nonheme Iron-Dependent Oxidative Enzyme during RiPP Biosynthesis.

bioRxiv : the preprint server for biology·2026
Same author

Metabolism and Excretion of Synthetic Extended Viperin Pathway Deoxydidehydronucleosides in the Sprague-Dawley Rat.

Journal of proteome research·2026

関連する実験動画

Updated: Jun 2, 2026

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues
12:07

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues

Published on: November 22, 2014

ラジカルSAM酵素によるメチル転送の構造的基礎

Amie K Boal1, Tyler L Grove, Monica I McLaughlin

  • 1Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.

Science (New York, N.Y.)
|April 30, 2011
PubMed
まとめ

ラジカルS-アデノシル-L-メチオニン (SAM) 酵素RlmNとCfrメチラート23SリボソームRNA. 構造研究は,RlmNは単一のSAM分子と活性部位を使用して,その複雑なメチル化反応を実行することを明らかにしています.

科学分野:

  • バイオケミストリー バイオケミストリー
  • 分子生物学は分子生物学である.
  • 構造生物学 構造生物学とは

背景:

  • ラジカルS-アデノシル-L-メチオニン (SAM) 酵素RlmNとCfrは,23SリボソームRNAをメチル化するために重要である.
  • このメチル化は,アデノシン2503のC2またはC8位置で発生し,リボソーム機能に影響を与えます.

研究 の 目的:

  • RlmNがリボソームRNA甲基化のためにS-アデノシル-L-メチオニン (SAM) を利用する構造的メカニズムを解明する.
  • RlmNが単一の活性部位内で複雑な2段階メチル化プロセスをどのように達成するのかを理解する.

主な方法:

  • X線結晶学を用いて,RlmNとSAMとの複合体の構造を決定した.
  • 構造分析は, [4Fe-4S] クラスタの調整と,主要残留物とSAMの位置づけに焦点を当てた.

主要な成果:

  • クリスタル構造は,単一のSAM分子が,RlmNの [4Fe-4S] クラスタを調整していることを明らかにしました.
  • 保存されたCys(355) 残基はS-メチル化され,SAMメチル群の近くに位置し,両方のメチル化段階の共通の結合部位を示しています.
  • これは,RlmNは,SAM依存反応の両方のサイトを1つ利用することによって,構造的経済を採用することを示唆しています.

さらに関連する動画

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
14:22

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

Published on: April 15, 2013

Antibody-Free Assay for RNA Methyltransferase Activity Analysis
08:31

Antibody-Free Assay for RNA Methyltransferase Activity Analysis

Published on: July 9, 2019

関連する実験動画

Last Updated: Jun 2, 2026

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues
12:07

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues

Published on: November 22, 2014

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
14:22

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

Published on: April 15, 2013

Antibody-Free Assay for RNA Methyltransferase Activity Analysis
08:31

Antibody-Free Assay for RNA Methyltransferase Activity Analysis

Published on: July 9, 2019

結論:

  • RlmNは,SAM結合とメチル転送のための単一の活性部位を利用することによって,23SリボソームRNAの2段階メチル化を効率的に触媒化する.
  • 酵素は,SAMの独特の反応性を構造的に保存された結合ポケットの中で活用し,エレガントな生化学的メカニズムを披露します.