Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Improving Translational Accuracy

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...

Proofreading

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

Proofreading

Proofreading

Mismatch Repair

Mismatch Repair

Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...

Mismatch Repair

Mismatch Repair

Allosteric Proteins-ATCase

Allosteric Proteins-ATCase

Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...

You might also read

Related Articles

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

Sort by

Same author

Symbiotic peptides modulate rhizobial physiology without terminal differentiation.

Science advances·2026

Same author

A Revised Model for Muscarine Biosynthesis Involving Lysine Trimethylation.

Angewandte Chemie (International ed. in English)·2026

Same author

Distal peptide elongation by a protease-like ligase and two distinct carrier proteins.

Chem·2026

Same author

Microbial dl-Peptidases Enable Predator Defense and Facilitate Structure Elucidation of Complex Natural Products.

Journal of the American Chemical Society·2026

Same author

Inactivation of the Burkholderia Toxin Malleicyprol by Enzymatic Cyclopropanol Ring Opening.

Angewandte Chemie (International ed. in English)·2025

Same author

Peptide Arginases from Cryptic Pathways Install Ornithine Residues in Uncharacterized Members of Orphan RiPP Families.

Chembiochem : a European journal of chemical biology·2025

Search research articles

Related Experiment Video

Updated: May 23, 2026

Proofreading and DNA Repair Assay Using Single Nucleotide Extension and MALDI-TOF Mass Spectrometry Analysis

Proofreading and DNA Repair Assay Using Single Nucleotide Extension and MALDI-TOF Mass Spectrometry Analysis

Published on: June 19, 2018

Polyketide proofreading by an acyltransferase-like enzyme.

Katja Jensen¹, Holger Niederkrüger, Katrin Zimmermann

¹Kekulé Institute of Organic Chemistry and Biochemistry, University of Bonn, 53121 Bonn, Germany.

Chemistry & Biology

|March 27, 2012

Summary

Researchers identified a novel proofreading role for AT2 enzymes in trans-acyltransferase polyketide synthases (trans-AT PKSs). This discovery offers new strategies for improving polyketide production and biosynthetic studies.

More Related Videos

A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli

A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli

Published on: December 9, 2017

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

Published on: January 13, 2017

Related Experiment Videos

Last Updated: May 23, 2026

Proofreading and DNA Repair Assay Using Single Nucleotide Extension and MALDI-TOF Mass Spectrometry Analysis

Proofreading and DNA Repair Assay Using Single Nucleotide Extension and MALDI-TOF Mass Spectrometry Analysis

Published on: June 19, 2018

A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli

A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli

Published on: December 9, 2017

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

Published on: January 13, 2017

Area of Science:

Biochemistry
Molecular Biology
Microbial Biotechnology

Background:

Trans-acyltransferase polyketide synthases (trans-AT PKSs) are crucial bacterial enzymes for synthesizing bioactive polyketides.
Unlike canonical PKSs, trans-AT PKSs feature accessory acyltransferase (AT)-like enzymes, with the function of a second AT copy (AT2) remaining largely uncharacterized.

Purpose of the Study:

To elucidate the function of the AT2 enzyme, PedC, within the pederin biosynthesis pathway.
To investigate the enzymatic activities of PedC and its homolog PedD in relation to acyl carrier proteins (ACPs).

Main Methods:

Enzymatic assays were performed to determine the substrate specificity and catalytic activity of PedC and PedD.
The hydrolysis and transfer activities of PedC and PedD towards various acyl units bound to N-acetylcysteamine and ACPs were assessed.

Main Results:

PedD exhibited malonyltransferase activity, indicating its role in loading PKS modules.
PedC (AT2) demonstrated efficient hydrolysis of acyl units from N-acetylcysteamine and ACPs, but notably did not cleave malonyl-ACP.
PedC accepted a range of acyl substrates with varying chain lengths and functionalizations, distinguishing it from PedD.

Conclusions:

The data strongly suggest that PedC functions as a PKS proofreading enzyme, removing incorrectly loaded acyl units.
This finding implies a conserved proofreading role for AT2 enzymes across other trans-AT PKS systems.
Understanding this mechanism provides avenues for enhancing polyketide production yields and advancing biosynthetic pathway engineering.