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

pre-mRNA Processing02:01

pre-mRNA Processing

In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
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...
Improving Translational Accuracy02:07

Improving Translational Accuracy

Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
Initiation of Translation02:33

Initiation of Translation

Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Pre-mRNA Processing: Modification of pre-mRNA Ends01:35

Pre-mRNA Processing: Modification of pre-mRNA Ends

In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps the cell...

You might also read

Related Articles

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

Sort by
Same author

Republicans subtly reform US medicine.

BMJ (Clinical research ed.)·1995
Same author

Age-related changes in cardiac norepinephrine release: role of calcium movement.

The journals of gerontology. Series A, Biological sciences and medical sciences·1995
Same author

US proposes radical reform of Medicare.

BMJ (Clinical research ed.)·1995
Same author

US warns against early discharge of babies.

BMJ (Clinical research ed.)·1995
Same author

Medicare plans outrage elderly people and doctors.

BMJ (Clinical research ed.)·1995
Same author

US apologises for radiation tests on unaware patients.

BMJ (Clinical research ed.)·1995

Related Experiment Video

Updated: May 9, 2026

In vitro tRNA Methylation Assay with the Entamoeba histolytica DNA and tRNA Methyltransferase Dnmt2 (Ehmeth) Enzyme
12:36

In vitro tRNA Methylation Assay with the Entamoeba histolytica DNA and tRNA Methyltransferase Dnmt2 (Ehmeth) Enzyme

Published on: October 20, 2010

In vitro processing of E. coli tRNA precursors

P Schedl, J Roberts, P Primakoff

    Cell
    |August 1, 1976
    PubMed
    Summary

    This study investigated tRNA precursor processing in E. coli using an RNAase P mutant. Results indicate at least three distinct enzymatic activities are involved in forming mature transfer RNAs (tRNAs).

    Area of Science:

    • Molecular Biology
    • Biochemistry
    • Genetics

    Background:

    • Transfer RNA (tRNA) is crucial for protein synthesis.
    • Accurate tRNA maturation involves precise processing of precursor molecules.
    • RNAase P is a key enzyme in tRNA processing.

    Purpose of the Study:

    • To investigate the enzymatic steps in tRNA precursor processing in vitro.
    • To identify the factors involved in generating mature tRNA primary sequences.
    • To understand the role of RNAase P mutants in tRNA maturation.

    Main Methods:

    • Isolation of E. coli tRNA precursors from an RNAase P mutant strain.
    • In vitro analysis of tRNA precursor processing.
    • Enzymatic assays to identify processing activities.

    More Related Videos

    Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses
    11:19

    Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses

    Published on: February 26, 2011

    Analysis of RNA Processing Reactions Using Cell Free Systems: 3' End Cleavage of Pre-mRNA Substrates in vitro
    09:16

    Analysis of RNA Processing Reactions Using Cell Free Systems: 3' End Cleavage of Pre-mRNA Substrates in vitro

    Published on: May 3, 2014

    Related Experiment Videos

    Last Updated: May 9, 2026

    In vitro tRNA Methylation Assay with the Entamoeba histolytica DNA and tRNA Methyltransferase Dnmt2 (Ehmeth) Enzyme
    12:36

    In vitro tRNA Methylation Assay with the Entamoeba histolytica DNA and tRNA Methyltransferase Dnmt2 (Ehmeth) Enzyme

    Published on: October 20, 2010

    Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses
    11:19

    Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses

    Published on: February 26, 2011

    Analysis of RNA Processing Reactions Using Cell Free Systems: 3' End Cleavage of Pre-mRNA Substrates in vitro
    09:16

    Analysis of RNA Processing Reactions Using Cell Free Systems: 3' End Cleavage of Pre-mRNA Substrates in vitro

    Published on: May 3, 2014

    Main Results:

    • Demonstrated the feasibility of in vitro tRNA maturation from precursor molecules.
    • Identified multiple enzymatic activities contributing to tRNA processing.
    • Characterized the processing steps in the absence of functional RNAase P.

    Conclusions:

    • At least three distinct enzymatic activities are required for mature tRNA formation.
    • tRNA processing is a complex pathway involving multiple enzymes.
    • Further research can elucidate the specific roles of these enzymatic activities.