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

Yeast Signaling01:28

Yeast Signaling

14.7K
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
14.7K
Allosteric Proteins-ATCase01:19

Allosteric Proteins-ATCase

5.8K
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...
5.8K
Allosteric Regulation01:08

Allosteric Regulation

58.4K
Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or...
58.4K
ATP Synthase: Structure01:18

ATP Synthase: Structure

12.8K
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
12.8K
ATP Synthase: Mechanism01:48

ATP Synthase: Mechanism

14.9K
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased...
14.9K
Protein Complexes with Interchangeable Parts01:57

Protein Complexes with Interchangeable Parts

2.6K
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
2.6K

You might also read

Related Articles

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

Sort by
Same author

A reversible feedback mechanism regulating mitochondrial heme synthesis.

bioRxiv : the preprint server for biology·2025
Same author

Elucidating the Role of Human ALAS2 C-terminal Mutations Resulting in Loss of Function and Disease.

Biochemistry·2024
Same author

Cellular context of IL-33 expression dictates impact on anti-helminth immunity.

Science immunology·2020
See all related articles

Related Experiment Video

Updated: Aug 9, 2025

Enzymatic Modification and Flow Cytometry Assessment of Yeast Surface Displayed Proteins
10:54

Enzymatic Modification and Flow Cytometry Assessment of Yeast Surface Displayed Proteins

Published on: May 30, 2025

317

The yeast ALA synthase C-terminus positively controls enzyme structure and function.

Jenny U Tran1, Breann L Brown1,2

  • 1Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.

Protein Science : a Publication of the Protein Society
|February 22, 2023
PubMed
Summary

The eukaryotic C-terminus of 5-aminolevulinic acid synthase (ALAS) is crucial for regulating heme biosynthesis. Its removal alters enzyme structure, decreasing activity and cooperativity, suggesting a role in autoregulation.

Keywords:
X-ray crystallographyallosteryaminolevulinic acid synthaseautoregulationheme biosynthesispyridoxal 5′-phosphatestructure

More Related Videos

Cycloheximide Chase Analysis of Protein Degradation in Saccharomyces cerevisiae
09:05

Cycloheximide Chase Analysis of Protein Degradation in Saccharomyces cerevisiae

Published on: April 18, 2016

29.1K
A Method to Study α-Synuclein Toxicity and Aggregation Using a Humanized Yeast Model
08:24

A Method to Study α-Synuclein Toxicity and Aggregation Using a Humanized Yeast Model

Published on: November 25, 2022

2.3K

Related Experiment Videos

Last Updated: Aug 9, 2025

Enzymatic Modification and Flow Cytometry Assessment of Yeast Surface Displayed Proteins
10:54

Enzymatic Modification and Flow Cytometry Assessment of Yeast Surface Displayed Proteins

Published on: May 30, 2025

317
Cycloheximide Chase Analysis of Protein Degradation in Saccharomyces cerevisiae
09:05

Cycloheximide Chase Analysis of Protein Degradation in Saccharomyces cerevisiae

Published on: April 18, 2016

29.1K
A Method to Study α-Synuclein Toxicity and Aggregation Using a Humanized Yeast Model
08:24

A Method to Study α-Synuclein Toxicity and Aggregation Using a Humanized Yeast Model

Published on: November 25, 2022

2.3K

Area of Science:

  • Biochemistry
  • Enzymology
  • Structural Biology

Background:

  • 5-Aminolevulinic acid synthase (ALAS) is a key PLP-dependent enzyme in heme biosynthesis.
  • Eukaryotic ALAS possesses a unique C-terminal extension involved in enzyme regulation, with mutations linked to human blood disorders.

Purpose of the Study:

  • To investigate the structural and functional importance of the C-terminal extension in Saccharomyces cerevisiae ALAS (Hem1).
  • To elucidate the role of C-terminal interactions in ALAS enzyme regulation and heme biosynthesis.

Main Methods:

  • Determined the crystal structure of Hem1 lacking the C-terminal extension (Hem1 ΔCT).
  • Performed biochemical analyses to assess enzyme activity, catalytic efficiency, and subunit cooperativity.

Main Results:

  • Truncation of the C-terminus resulted in increased flexibility of catalytic motifs, including a critical β-sheet.
  • Observed an altered cofactor microenvironment, reduced enzyme activity and catalytic efficiency, and loss of subunit cooperativity in Hem1 ΔCT.

Conclusions:

  • The eukaryotic ALAS C-terminus plays a vital, homolog-specific role in mediating heme biosynthesis.
  • This C-terminal region acts as a mechanism for autoregulation, offering potential for allosteric modulation of heme biosynthesis.