プロカリオットおよびユカリオットDNAポリメラーゼの保存された3'----5'エクゾヌクレアース活性部位
A Bernad1, L Blanco, J M Lázaro
1Centro de Biologia Molecular (CSIC-UAM), Universidad Autónoma, Madrid, Spain.
Cell
|October 6, 1989
まとめ
その3 その3 その3 その3
科学分野:
- 分子生物学は分子生物学である.
- 酵素学 酵素学とは
- 進化生物学の進化生物学について
背景:
- DNAポリメラーゼは,DNA修復と複製のための重要な3'から5'エクソヌクレアゼ活性を持っています.
- 配列ホモロジーは,プロカリオットおよびエウカリオットDNAポリメラーゼにわたって保存された活性部位を示唆する.
研究 の 目的:
- DNAポリメラーゼにおける3'から5'エクソヌクレアース活性部位の進化的保存を調査する.
- phi 29 DNAポリメラーゼにおけるサイト指向型変異遺伝子を用いて機能保存を検証する.
主な方法:
- E. coliのDNAポリメラーゼIのアミノ酸配列ホモロジー分析. 他のポリメラーゼと.
- phi29 DNAポリメラーゼの予測されたエクソヌクレアース活性部位のサイト指向型変異.
主要な成果:
- 保存されたアミノ酸領域を特定し,金属結合,DNA結合,およびプロカリオットおよび真核細胞のDNAポリメラーゼにおける触媒に不可欠である.
- phi29DNAポリメラーゼの変異は,その3'から5'エクソヌクレアゼの活性を廃止し,機能的保存を確認した.
- この触媒領域の高度な進化的保存を示した.
結論:
- 3'から5'エクソヌクレアスの活性部位は,様々なDNAポリメラーゼで高度に保存されています.
- プロカリオットおよびエウカリオットDNAポリメラーゼのための酵素活動のモジュール型組織が提案されています.
関連する概念動画
Replication in Eukaryotes
Overview
Proofreading
Synthesis of new DNA molecules starts when DNA polymerase links nucleotides together in a sequence that is complementary to the template DNA strand. DNA polymerase has a higher affinity for the correct base to ensure fidelity in DNA replication. The DNA polymerase furthermore proofreads during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.Errors during Replication Are Corrected by the DNA Polymerase EnzymeGenomic DNA is synthesized in...
The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
Translesion DNA Polymerases
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
Proofreading
Synthesis of new DNA molecules is carried out by the enzyme DNA polymerase, which adds nucleotides on the daughter strand complementary to the template DNA strand. DNA polymerase has a higher affinity to add the correct base and ensures fidelity during DNA replication. Furthermore, it exhibits proofreading activity during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.
Errors During Replication are Corrected by the DNA Polymerase Enzyme
Errors During Replication are Corrected by the DNA Polymerase Enzyme
Replication in Eukaryotes
In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...


