Related Experiment Video

Updated: Sep 28, 2026

Kinetics of Lagging-strand DNA Synthesis In Vitro by the Bacteriophage T7 Replication Proteins
08:14

Kinetics of Lagging-strand DNA Synthesis In Vitro by the Bacteriophage T7 Replication Proteins

Published on: February 25, 2017

[The kinetic mechanism of phage T4 DNA-[N6-adenine]-methyltransferase]

A A Evdokimov1, V V Zinov'ev, E G Malygin

  • 1Institute of Molecular Biology, State Research Center for Virology and Biotechnology VECTOR, Kol'tsovo, Novosibirsk Region, 633159 Russia.

Molekuliarnaia Biologiia
|October 24, 2002
PubMed

Insights

The phage T4 DNA methyltransferase reaction, transferring methyl groups from S-adenosyl-L-methionine (SAM) to DNA, is significantly faster in the forward direction. The enzyme mechanism involves ordered steps and potential isomerization.

Area of Science:

  • Biochemistry
  • Enzymology
  • Molecular Biology

Context:

  • Investigates the kinetic mechanism of phage T4 DNA-[N6-adenine]-methyltransferase (MTase) [EC 2.1.1.72].
  • Focuses on methyl group transfer from S-adenosyl-L-methionine (SAM) to the GATC DNA recognition site.

Purpose:

  • To elucidate the kinetic pathway and mechanism of the T4 DNA MTase.
  • To determine the rate and order of substrate binding and product release.

Summary:

  • The reverse reaction is over 500 times slower than the forward reaction, indicating a highly directional process.
  • Product inhibition patterns suggest an ordered steady-state mechanism: SAM binds, followed by DNA, then SAH is released.
  • High substrate concentrations revealed complex kinetics, including potential dead-end complex formation and a concerted SAM binding/SAH release event.

Impact:

  • Provides detailed mechanistic insights into DNA methylation by phage T4 MTase.
  • The findings contribute to understanding enzyme kinetics and reaction mechanisms in DNA modification.
  • Suggests enzyme isomerization as a key step in the catalytic cycle.

More Related Videos

Precise Phage Mutagenesis with NgTET-Assisted CRISPR-Cas Systems10:52

Precise Phage Mutagenesis with NgTET-Assisted CRISPR-Cas Systems

Published on: October 14, 2025

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues12:07

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

Published on: November 22, 2014

Related Concept Videos

DNA Bacteriophages01:26

DNA Bacteriophages

Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
Viral Replication: Lytic Cycle01:20

Viral Replication: Lytic Cycle

Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
Transfer RNA Synthesis02:36

Transfer RNA Synthesis

One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Proofreading01:43

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...
Proofreading01:31

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
ATP Synthase: Mechanism01:48

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...