イーストポリ (A) ポリメラーゼ単体および3'-dATPとの複合体における構造

J Bard¹, A M Zhelkovsky, S Helmling

¹Boston Biomedical Research Institute, 64 Grove Street, Watertown, MA 02472, USA.

Science (New York, N.Y.)

|August 26, 2000

まとめ

酵母ポリアデニラートポリメラーゼ (PAP) の結晶構造は,ユニークなドメイン配列を明らかにします. ヌクレオチドアナログに結合したこの構造は,mRNAポリアデニレーションの洞察を提供します.

科学分野:

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

背景:

ポリアデニラート[poly(A) ]ポリメラーゼ (PAP) は,真核伝達 RNA (mRNA) にポリアデノシン尾を加えるのに不可欠です.
PAPの構造を理解することは,mRNAの処理メカニズムを明らかにするために重要です.

研究の目的:

Saccharomyces cerevisiaeのポリアデニlateポリメラーゼ (Pap1) の結晶構造を決定するために.
ヌクレオチドアナログによる複合形成によるPap1の酵素活性の構造的基礎を調査する.

主な方法:

X線結晶学を用いて,Pap1.1の結晶構造を解明しました.
アポエンザイムと3'-デオキシアデノシン三リン酸塩 (3'-dATP) の複合体の両方の構造が決定されました.

主要な成果:

Pap1の結晶構造は2.6アングストームの解像度で解明されました.
Pap1は活性部位を囲む3ドメイン構造を示しており,テンプレート依存ポリメラーゼとは異なる.
2つの3'-dATP分子がPap1に結合し,入ってくるヌクレオチドとmRNAプライマーの3'端の位置を占める.

結論:

Pap1のユニークなドメインの配置は,その非テンプレート核酸添加のための構造的基礎を提供します.
3'-dATPの結合は,ポリアデニレーション中のニュクレオチド結合とプライマー相互作用のメカニズムを示唆する.

さらに関連する動画

10:39

Visualization of ATP Synthase Dimers in Mitochondria by Electron Cryo-tomography

Published on: September 14, 2014

10:23

Self-assembly of Complex Two-dimensional Shapes from Single-stranded DNA Tiles

Published on: May 8, 2015

関連する概念動画

02:41

Protein Complex Assembly

Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...

00:55

DNA Helicases

DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...

01:48

ATP Synthase: Mechanism

In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...

01:18

ATP Synthase: Structure

ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...

01:19

Allosteric Proteins-ATCase

Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...

01:25

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA has a double-helix structure. The...

関連する実験動画