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

Transfer RNA Synthesis

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...

tRNA Activation

tRNA Activation

Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...

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...

Transfer RNA Synthesis

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...

tRNA Activation

tRNA Activation

Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...

Amino Acid Biosynthetic Pathways

Amino Acid Biosynthetic Pathways

Amino acid biosynthesis is essential for cell growth, protein synthesis, and metabolic regulation. Cells generate essential and non-essential amino acids from metabolic intermediates to sustain vital biological functions. These intermediates originate from key metabolic pathways: glycolysis, the tricarboxylic acid (TCA) cycle, and the pentose phosphate pathway. Important precursors include α-ketoglutarate, pyruvate, oxaloacetate, phosphoenolpyruvate, and erythrose-4-phosphate, which provide...

You might also read

Related Articles

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

Sort by

Same author

Testing commercial biopreservative against spoilage microorganisms in MAP packed Ricotta fresca cheese.

Food microbiology·2017

Same author

Overcoming Challenges in Engineering the Genetic Code.

Journal of molecular biology·2015

Same author

The nucleotide sequences of barley cytoplasmic glutamate transfer RNAs and structural features essential for formation of δ-aminolevulinic acid.

Plant molecular biology·2013

Same author

Prenatal restraint stress: an in vivo microdialysis study on catecholamine release in the rat prefrontal cortex.

Neuroscience·2010

Same author

Prepuberal subchronic methylphenidate and atomoxetine induce different long-term effects on adult behaviour and forebrain dopamine, norepinephrine and serotonin in Naples high-excitability rats.

Behavioural brain research·2010

Same author

Cys-tRNACys formation and cysteine biosynthesis in methanogenic archaea: two faces of the same problem?

Cellular and molecular life sciences : CMLS·2004

Search research articles

Related Experiment Video

Updated: Jul 11, 2026

Genome-wide Analysis of Aminoacylation (Charging) Levels of tRNA Using Microarrays

Genome-wide Analysis of Aminoacylation (Charging) Levels of tRNA Using Microarrays

Published on: June 19, 2010

Glutaminyl-tRNA synthetase

W Freist¹, D H Gauss, M Ibba

¹Max-Planck-Institut für experimentelle Medizin, Göttingen, Germany.

Biological Chemistry

|February 12, 1998

Summary

Glutaminyl-tRNA synthetase (GlnRS) is a unique enzyme absent in many organisms. Its structure and function, particularly tRNA recognition, were elucidated through crystal structures and mutant analysis in E. coli.

Area of Science:

Biochemistry
Molecular Biology
Structural Biology

Background:

Glutaminyl-tRNA synthetase (GlnRS) is one of twenty aminoacyl-tRNA synthetases, notable for its absence in certain organisms like gram-positive eubacteria, archaebacteria, and organelles.
The Escherichia coli GlnRS is a monomer of 553 amino acids (64.4 kDa), contrasting with larger mammalian counterparts that can form multienzyme complexes.

Purpose of the Study:

To elucidate the structural basis of glutaminyl-tRNA synthetase function.
To investigate the mechanism of tRNA recognition by GlnRS.
To understand the evolutionary relationship between GlnRS and glutamyl-tRNA synthetase.

Main Methods:

X-ray crystallography was employed to solve the structures of E. coli GlnRS in complex with tRNA(Gln) and ATP.

More Related Videos

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

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

Published on: February 26, 2011

Glutamine Flux Imaging Using Genetically Encoded Sensors

Glutamine Flux Imaging Using Genetically Encoded Sensors

Published on: July 31, 2014

Related Experiment Videos

Last Updated: Jul 11, 2026

Genome-wide Analysis of Aminoacylation (Charging) Levels of tRNA Using Microarrays

Genome-wide Analysis of Aminoacylation (Charging) Levels of tRNA Using Microarrays

Published on: June 19, 2010

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

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

Published on: February 26, 2011

Glutamine Flux Imaging Using Genetically Encoded Sensors

Glutamine Flux Imaging Using Genetically Encoded Sensors

Published on: July 31, 2014

Structures were also determined for complexes with unmodified tRNA(Gln) and mutated GlnRS enzymes.

Mutagenesis studies using natural and artificial mutants of tRNA(Gln) and GlnRS were performed to analyze enzyme-tRNA recognition.

Main Results:

The GlnRS molecule comprises four domains, with the catalytic site located in a Rossmann fold, characteristic of class I synthetases.
The reaction mechanism follows the canonical adenylate pathway.
GlnRS primarily recognizes conventional tRNA elements, including specific bases in the anticodon loop and acceptor stem, for cognate tRNA binding.

Conclusions:

The study provides detailed structural and mechanistic insights into glutaminyl-tRNA synthetase function.
GlnRS shares significant similarities with glutamyl-tRNA synthetase, supporting a common evolutionary origin.
The findings clarify the molecular basis of GlnRS-tRNA recognition in the E. coli system.