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

Ligand Binding and Linkage

Ligand Binding and Linkage

Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...

Assembly of Signaling Complexes

Assembly of Signaling Complexes

Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...

Enzymes

Enzymes

Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...

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,...

Induced-fit Model

Induced-fit Model

Most chemical reactions in cells require enzymes—biological catalysts that speed up the reaction without being consumed or permanently changed. They reduce the activation energy needed to convert the reactants into products. Enzymes are proteins, that usually work by binding to a substrate—a reactant molecule that they act upon.
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical characteristics of...

Cooperative Allosteric Transitions

Cooperative Allosteric Transitions

Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...

You might also read

Related Articles

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

Sort by

Same author

Thermodynamic and Allosteric Drivers of Stilbene-Mediated Noncompetitive Inhibition of Firefly Luciferase.

Biochemistry·2026

Same author

A Divergent MBL-Fold Metallo-Hydrolase (Kmh-1) from <i>Klebsiella pneumoniae</i> Confers Aztreonam Degradation and Expands the β-Lactamase Landscape.

ACS infectious diseases·2026

Same author

Correction: A mammalian, glutaminase-free asparaginase enhances venetoclax activity in preclinical AML models with chromosome 7 deletion.

Frontiers in oncology·2026

Same author

Decoding the genome of multidrug resistant (MDR) <i>Providencia hangzhouensis</i> from a cerebrospinal fluid infection isolated from the hospital of Kolkata, West Bengal, India.

Microbiology resource announcements·2026

Same author

Agro-Industrial Waste Valorization for Sustainable PHBV Production from Sugarcane Bagasse Using <i>Bacillus</i> sp. HLI02.

Polymers·2026

Same author

Draft-genome sequencing of multidrug-resistant hypervirulent <i>Klebsiella pneumoniae</i> from neonatal septicaemia at SRHU, Dehradun, India.

Microbiology resource announcements·2026

Search research articles

Related Experiment Video

Updated: Jul 6, 2026

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach

Published on: February 21, 2019

Structural basis for substrate promiscuity of dCK.

Elisabetta Sabini¹, Saugata Hazra, Stephan Ort

¹Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA.

Journal of Molecular Biology

|April 2, 2008

Summary

Deoxycytidine kinase (dCK) structure reveals how it accepts diverse substrates. The enzyme

More Related Videos

Defining Substrate Specificities for Lipase and Phospholipase Candidates

Defining Substrate Specificities for Lipase and Phospholipase Candidates

Published on: November 23, 2016

Identification of Kinase-substrate Pairs Using High Throughput Screening

Identification of Kinase-substrate Pairs Using High Throughput Screening

Published on: August 29, 2015

Related Experiment Videos

Last Updated: Jul 6, 2026

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach

Published on: February 21, 2019

Defining Substrate Specificities for Lipase and Phospholipase Candidates

Defining Substrate Specificities for Lipase and Phospholipase Candidates

Published on: November 23, 2016

Identification of Kinase-substrate Pairs Using High Throughput Screening

Identification of Kinase-substrate Pairs Using High Throughput Screening

Published on: August 29, 2015

Area of Science:

Biochemistry
Structural Biology
Enzymology

Background:

Deoxycytidine kinase (dCK) is vital for DNA synthesis and prodrug activation.
dCK phosphorylates deoxyadenosine, deoxyguanosine, and deoxycytidine, and accepts ATP or UTP as donors.
Understanding dCK's substrate promiscuity is key for drug development.

Purpose of the Study:

To elucidate the structural basis of dCK's substrate promiscuity.
To investigate how nucleotide donors (ATP vs. UTP) influence dCK conformation and substrate binding.

Main Methods:

X-ray crystallography of dCK ternary complexes.
Complexes formed with D-dA, L-dA, and either ADP or UDP.
Tryptophan fluorescence spectroscopy.

Main Results:

dCK adopts an open, non-catalytic conformation with UDP and dA.
dCK adopts a closed, catalytically competent conformation with ADP and dA.
Nucleotide donor type dictates dCK's conformational state and substrate binding.

Conclusions:

The nucleotide donor (ADP vs. UDP) influences dCK's active site conformation.
This conformational flexibility explains dCK's differential substrate interactions and kinetics.
Structural insights aid in designing dCK-activated prodrugs.