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

Translesion DNA Polymerases02:10

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...
DNA-only Transposons02:57

DNA-only Transposons

DNA-only transposons are called autonomous transposons since they code for the enzyme transposase that is required for the transposition mechanism. Insertion of transposons can alter gene functions in multiple ways. They can mutate the gene, alter gene expression by introducing a novel promoter or insulator sequence, introduce new splice sites, and change the mRNA transcripts produced, or remodel chromatin structure.
The donor site from where the transposon is excised is either degraded or...
Retroviruses02:33

Retroviruses

Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
LTR Retrotransposons03:08

LTR Retrotransposons

LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila.
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
Non-LTR Retrotransposons03:18

Non-LTR Retrotransposons

As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
Viruses with RNA Genomes01:29

Viruses with RNA Genomes

RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...

You might also read

Related Articles

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

Sort by
Same author

Climate change and the integrity of science.

Science (New York, N.Y.)·2010
Same author

Sequence-specific single-strand RNA binding protein encoded by the human LINE-1 retrotransposon.

The EMBO journal·1997
Same author

Ribonuclease and high salt sensitivity of the ribonucleoprotein complex formed by the human LINE-1 retrotransposon.

Journal of molecular biology·1997
Same author

Genetic testing and insurance.

Nature·1996
Same author

Cytoplasmic ribonucleoprotein complexes containing human LINE-1 protein and RNA.

The EMBO journal·1996
Same author

Unusual reverse transcriptases.

The Journal of biological chemistry·1995

Related Experiment Video

Updated: Jul 13, 2026

Amplification of Near Full-length HIV-1 Proviruses for Next-Generation Sequencing
10:18

Amplification of Near Full-length HIV-1 Proviruses for Next-Generation Sequencing

Published on: October 16, 2018

The human LINE-1 reverse transcriptase:effect of deletions outside the common reverse transcriptase domain

A P Clements1, M F Singer

  • 1Laboratory of Biochemistry, National Cancer Institute, Building 37, Room 4A-01, Bethesda, MD 20892, USA.

Nucleic Acids Research
|July 22, 1998
PubMed
Summary

The Z region of LINE-1 ORF2 protein is crucial for reverse transcriptase activity. Specific amino acid changes in this region, but not in the endonuclease or cysteine-rich domains, abolish enzyme function.

More Related Videos

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells
13:07

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells

Published on: January 30, 2019

Detection of Retrotransposition Activity of Hot LINE-1s by Long-Distance Inverse PCR
10:54

Detection of Retrotransposition Activity of Hot LINE-1s by Long-Distance Inverse PCR

Published on: July 27, 2019

Related Experiment Videos

Last Updated: Jul 13, 2026

Amplification of Near Full-length HIV-1 Proviruses for Next-Generation Sequencing
10:18

Amplification of Near Full-length HIV-1 Proviruses for Next-Generation Sequencing

Published on: October 16, 2018

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells
13:07

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells

Published on: January 30, 2019

Detection of Retrotransposition Activity of Hot LINE-1s by Long-Distance Inverse PCR
10:54

Detection of Retrotransposition Activity of Hot LINE-1s by Long-Distance Inverse PCR

Published on: July 27, 2019

Area of Science:

  • Molecular Biology
  • Genetics
  • Biochemistry

Background:

  • LINE-1 elements are retrotransposons essential for genome plasticity.
  • LINE-1 ORF2 protein possesses both endonuclease and reverse transcriptase activities.
  • Understanding ORF2 protein function is key to LINE-1 biology.

Purpose of the Study:

  • To investigate the functional domains of the human LINE-1 ORF2 protein.
  • To identify regions critical for reverse transcriptase activity.

Main Methods:

  • Heterologous expression of human LINE-1 ORF2 and its deletion derivatives in yeast.
  • Co-purification of ORF2 protein with reverse transcriptase activity.
  • Reverse transcriptase assays using synthetic polynucleotides.
  • Site-directed mutagenesis of conserved regions.

Main Results:

  • ORF2 protein expressed in yeast exhibits reverse transcriptase activity.
  • Deletion of the N-terminal endonuclease domain retains partial activity.
  • Deletion of the C-terminal cysteine-rich motif has minimal impact on activity.
  • Deletions within the Z motif region, particularly near the polymerase domain, abolish activity.
  • Mutations in the conserved Z8 octapeptide sequence can inactivate the enzyme.

Conclusions:

  • The Z region, including the Z8 octapeptide, is essential for LINE-1 ORF2 reverse transcriptase activity.
  • The endonuclease and cysteine-rich domains are not strictly required for reverse transcriptase function.
  • These findings provide insights into the structure-function relationship of LINE-1 reverse transcriptase.