Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Multi-pass Transmembrane Proteins and β-barrels01:09

Multi-pass Transmembrane Proteins and β-barrels

5.9K
In multi-pass transmembrane proteins, the polypeptide chain crosses the membrane more than once. The transmembrane polypeptide chain either forms an α-helix or β-strand structure. α-Helix containing multi-pass transmembrane proteins are ubiquitous, whereas β-strand containing ones are mainly found in gram-negative bacteria, mitochondria, and chloroplasts.
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as...
5.9K
Structure of Porins01:21

Structure of Porins

3.4K
Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a  motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel...
3.4K
Insertion of Multi-pass Transmembrane Proteins in the RER01:29

Insertion of Multi-pass Transmembrane Proteins in the RER

14.7K
The rough ER membrane synthesizes, assembles, and embeds transmembrane proteins in diverse topologies. These proteins function as transporters or channels and can remain in the ER membrane or are sent to the Golgi complex, lysosome, and cell membrane.
The multipass transmembrane proteins are the type IV integral membrane proteins with multiple topogenic sequences determining their spatial arrangement in the ER membrane. Nearly all multipass proteins lack a cleavable signal sequence and use...
14.7K
Porin Insertion in the Outer Mitochondrial Membrane01:12

Porin Insertion in the Outer Mitochondrial Membrane

3.7K
Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
3.7K
Gram-negative Bacterial Protein Secretion Systems01:17

Gram-negative Bacterial Protein Secretion Systems

268
Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
268
Cytoskeletal Proteins in Bacteria01:29

Cytoskeletal Proteins in Bacteria

3.8K
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.8K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Prognostic impact of heart failure guideline-directed medical therapy in patients with low blood pressure.

Kardiologia polska·2026
Same author

Molecular Principles of Gating Proton Transport in the Antiporter Modules of Respiratory Complex I.

Journal of the American Chemical Society·2026
Same author

pLM-Repeat: Exploiting the sequence representations of protein language models for sensitive repeat detection.

Protein science : a publication of the Protein Society·2026
Same author

Upper Gastrointestinal Bleeding Due to Ruptured Gastric Varices: A Diagnostic Challenge.

Cureus·2026
Same author

Incremental value of implantable loop recorders in arrhythmia detection and management in cardiomyopathies: Prospective study.

Revista portuguesa de cardiologia : orgao oficial da Sociedade Portuguesa de Cardiologia = Portuguese journal of cardiology : an official journal of the Portuguese Society of Cardiology·2026
Same author

Functional Profiling of Kiwifruit Phyllosphere Bacteria: Copper Resistance and Biocontrol Potential as a Foundation for Microbiome-Informed Strategies.

Microorganisms·2026
Same journal

Costunolide ameliorates autoimmune uveitis by targeting USP15 to suppress TNF-α-induced retinal endothelial inflammation.

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

A ligandable PNT domain establishes ERG as a directly targetable oncogenic driver in prostate cancer.

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

Identification of cellular intermediates unveils unique enzymes for flagellar glycan biosynthesis in <i>Clostridioides difficile</i>.

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

The structure of correlated variability reflects task-relevant information in sensory neurons.

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

Shared neurogenetic substrates of nonplanning impulsivity and procrastination.

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

HIV-1 capsid interactions with Nuclear Pore Complex components support nuclear entry via affinity gradient.

Proceedings of the National Academy of Sciences of the United States of America·2026
See all related articles

Related Experiment Video

Updated: Oct 26, 2025

From Constructs to Crystals &#8211; Towards Structure Determination of &#946;-barrel Outer Membrane Proteins
09:55

From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins

Published on: July 4, 2016

13.7K

Gram-negative outer-membrane proteins with multiple β-barrel domains.

Ron Solan1, Joana Pereira2, Andrei N Lupas3

  • 1Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel.

Proceedings of the National Academy of Sciences of the United States of America
|July 31, 2021
PubMed
Summary
This summary is machine-generated.

Researchers discovered proteins with multiple outer-membrane beta barrels (OMBBs), challenging the notion of single-barrel proteins. These novel multibarrel proteins suggest new functional possibilities in bacteria and organelles.

Keywords:
coevolution analysis of bacterial sequencesevolutionary analysisgram-negative bacteriaouter-membrane beta barrelssequence analysis

More Related Videos

Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii
10:24

Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii

Published on: April 10, 2020

13.7K
Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification
10:21

Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification

Published on: November 16, 2016

13.6K

Related Experiment Videos

Last Updated: Oct 26, 2025

From Constructs to Crystals &#8211; Towards Structure Determination of &#946;-barrel Outer Membrane Proteins
09:55

From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins

Published on: July 4, 2016

13.7K
Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii
10:24

Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii

Published on: April 10, 2020

13.7K
Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification
10:21

Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification

Published on: November 16, 2016

13.6K

Area of Science:

  • Biochemistry
  • Structural Biology
  • Microbiology

Background:

  • Outer-membrane beta barrels (OMBBs) are crucial protein structures in gram-negative bacteria and eukaryotic organelles.
  • Known OMBBs typically consist of a single barrel, despite many functioning as oligomers.

Purpose of the Study:

  • To investigate the existence and prevalence of proteins containing multiple OMBBs within a single polypeptide chain.
  • To explore the evolutionary origins and potential functional implications of these multi-barrel proteins.

Main Methods:

  • Utilized sensitive sequence comparison techniques.
  • Employed coevolutionary analysis tools to identify multi-barrel protein candidates.

Main Results:

  • Identified numerous proteins composed of multiple OMBBs, with eight-stranded barrels being common.
  • These multibarrels appear to arise from independent gene fusion and amplification events across different lineages.
  • Multi-barrel proteins are not universally conserved, indicating lineage-specific adaptations rather than essential functions.

Conclusions:

  • The discovery of multi-OMBB proteins expands our understanding of protein architecture in biological membranes.
  • These proteins likely provide advantageous functions in specific environmental contexts.
  • Adjacent barrels within a single chain may enable novel, synergistic functions exceeding those of individual barrels.