Related Experiment Video

Updated: Jun 18, 2026

Membrane Transport Processes Analyzed by a Highly Parallel Nanopore Chip System at Single Protein Resolution
11:55

Membrane Transport Processes Analyzed by a Highly Parallel Nanopore Chip System at Single Protein Resolution

Published on: August 16, 2016

Translocation of double-stranded DNA through membrane-adapted phi29 motor protein nanopores

David Wendell1, Peng Jing, Jia Geng

  • 1Department of Biomedical Engineering, College of Engineering and College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA.

Nature Nanotechnology
|November 7, 2009
PubMed

Insights

Researchers engineered a modified bacteriophage phi29 DNA-packaging motor protein to create a channel capable of translocating double-stranded DNA. This breakthrough opens new avenues for DNA sequencing and gene delivery applications.

Area of Science:

  • Biophysics
  • Molecular Biology
  • Nanotechnology

Background:

  • Biological pores are crucial for molecular transport but often limited to small molecules or single-stranded nucleic acids.
  • The bacteriophage phi29 DNA-packaging motor possesses a wide channel (3.6-6 nm) facilitating double-stranded DNA translocation.

Purpose of the Study:

  • To engineer a membrane-integrated biological pore for double-stranded DNA translocation.
  • To assess the feasibility of using a modified bacteriophage connector protein for controlled molecular transport.

Main Methods:

  • Reconstitution of a modified bacteriophage phi29 connector protein into liposomes.
  • Insertion of functionalized liposomes into planar lipid bilayers.
  • Electrophysiological measurements to determine channel conductance.

Main Results:

  • The engineered phage connector successfully facilitated double-stranded DNA translocation across lipid bilayers.
  • A single connector channel exhibited a conductance of 4.8 nS in 1 M KCl.
  • The modified protein demonstrated membrane adaptation and functional pore formation.

Conclusions:

  • Engineered bacteriophage connectors represent a novel platform for creating functional nanopores.
  • This technology holds significant potential for applications in DNA sequencing, gene delivery, and biosensing.
  • The developed pore offers a controllable channel for double-stranded DNA, overcoming limitations of previous biological pores.

More Related Videos

Fine-tuning the Size and Minimizing the Noise of Solid-state Nanopores09:43

Fine-tuning the Size and Minimizing the Noise of Solid-state Nanopores

Published on: October 31, 2013

Visualization of Surface-tethered Large DNA Molecules with a Fluorescent Protein DNA Binding Peptide08:51

Visualization of Surface-tethered Large DNA Molecules with a Fluorescent Protein DNA Binding Peptide

Published on: June 23, 2016

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...
Intracellular Movement of Viruses and Bacteria01:10

Intracellular Movement of Viruses and Bacteria

Intracellular bacteria and viruses often comprise a group of highly infectious pathogens that can cause several diseases. Bacterial pathogens include those belonging to the genus Rickettsia responsible for conditions such as rocky mountain spotted fever and the Mediterranean spotted fever; Chlamydia, a genus responsible for a sexually transmitted disease; Coxiella burnetii, an agent responsible for Q fever. Viral pathogens include vaccinia—a poxvirus, and herpes simplex virus—a virus that...
Protein Transport into the Inner Mitochondrial Membrane01:34

Protein Transport into the Inner Mitochondrial Membrane

Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Cotranslational Protein Translocation01:20

Cotranslational Protein Translocation

Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
The Replisome03:01

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...
Protein Diffusion in the Membrane01:24

Protein Diffusion in the Membrane

Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...