Recombinant Human GATB Protein: Function & Research Use

Recombinant Human GATB Protein is a key mitochondrial enzyme subunit involved in the transamidation pathway required for the biosynthesis of correctly charged mitochondrial glutaminyl-tRNA and asparaginyl-tRNA, making it an essential reagent for researchers studying mitochondrial translation, tRNA biology, and related disease mechanisms.

Product Name

Recombinant Human GATB Protein

SKU

rp372885

Gene Name

GATB (also known as PET112L)

Protein Function

Amidotransferase subunit B of the mitochondrial GatCAB complex; catalyzes transamidation of mischarged tRNAs

Biological Process

Mitochondrial aminoacyl-tRNA biosynthesis via transamidation

Research Applications

Biochemical assays, protein interaction studies, structural biology, enzyme activity assays

What Is GATB? Gene and Protein Background

The GATB gene encodes the amidotransferase subunit B of the mitochondrial glutamyl-tRNA amidotransferase complex, commonly referred to as the GatCAB complex. This heterotrimer (comprising subunits GatA, GatB, and GatC) is responsible for the transamidation of mischarged mitochondrial tRNAs, specifically mt-tRNA^Gln and mt-tRNA^Asn. Because mitochondria lack dedicated glutaminyl-tRNA synthetase and asparaginyl-tRNA synthetase activities, they rely on this indirect pathway to produce correctly charged aminoacyl-tRNAs essential for mitochondrial translation.

The human GATB gene is orthologous to the bacterial gatB gene and its yeast counterpart PET112. GATB protein harbors an amidase fold responsible for the amidotransferase activity of the complex, accepting glutamine as an amide donor. Disruption of this pathway is associated with impaired mitochondrial protein synthesis and has been implicated in mitochondrial disease research.

Biochemical Function and Mechanism of Action

GATB is the catalytic amidotransferase subunit within the GatCAB heterotrimer. The reaction mechanism proceeds in two main steps. First, the GatA subunit hydrolyzes glutamine to release ammonia. Second, the ammonia is channeled to the active site of GatB, where it is used to amidate a mischarged glutamyl-mt-tRNA^Gln or aspartyl-mt-tRNA^Asn, converting them to correctly charged glutaminyl-mt-tRNA^Gln or asparaginyl-mt-tRNA^Asn, respectively. GatC is a small stabilizing subunit that supports complex integrity.

This transamidation mechanism is critical for maintaining the fidelity of mitochondrial translation. Impaired GATB function can lead to the accumulation of mischarged tRNAs, mistranslation of mitochondrially encoded proteins, and downstream defects in oxidative phosphorylation. As such, GATB is a subject of interest in studies of mitochondrial disorders, including those affecting the heart and skeletal muscle.

Research Applications of Recombinant Human GATB Protein

Recombinant Human GATB Protein (SKU: rp372885) is suitable for a range of in vitro biochemical and cell biology applications. Typical uses include:

• Enzyme activity assays: Characterizing the amidotransferase activity of GATB alone or within the reconstituted GatCAB complex.
• Protein–protein interaction studies: Investigating binding interfaces between GATB and its complex partners GatA and GatC, or identifying novel interactors by pull-down or co-immunoprecipitation assays.
• Structural biology: Use as an antigen for antibody production, or as a component in cryo-EM and X-ray crystallography studies of the GatCAB complex.
• Disease mechanism research: Modeling the molecular consequences of GATB variants associated with mitochondrial dysfunction.
• Drug discovery: Screening for small-molecule inhibitors or modulators of the mitochondrial transamidation pathway.

Researchers should verify specific activity, purity, and formulation details on the product datasheet prior to experimental use.

Handling, Storage, and Quality Considerations

As with all recombinant proteins, proper handling of Recombinant Human GATB Protein is essential to preserve activity and integrity. General best-practice recommendations include:

• Storage: Store at –80 °C for long-term stability. Avoid repeated freeze–thaw cycles, which can lead to protein aggregation and loss of activity. Aliquot into single-use volumes upon first thaw.
• Reconstitution: Follow the supplier's datasheet instructions precisely. Use the recommended buffer system; inappropriate pH or ionic strength may affect solubility and activity.
• Quality verification: Confirm protein identity and purity by SDS-PAGE or Western blot before use. Check for endotoxin levels if the protein is to be used in cell-based assays.
• Activity confirmation: Where possible, validate amidotransferase activity using an established in vitro assay before committing the protein to downstream experiments.

Consult the official product datasheet for Aladdin SKU rp372885 for lot-specific information including purity, formulation, and recommended storage conditions.

Frequently asked questions

What is the biological function of human GATB protein?

GATB is the amidotransferase B subunit of the mitochondrial GatCAB complex. It participates in the transamidation of mischarged mitochondrial tRNAs (mt-tRNA-Gln and mt-tRNA-Asn), converting them to correctly charged forms essential for accurate mitochondrial protein synthesis.

What applications is Recombinant Human GATB Protein (rp372885) suitable for?

This recombinant protein is suitable for enzyme activity assays, protein–protein interaction studies (e.g., pull-down, co-IP), structural biology investigations, disease mechanism modeling, and small-molecule drug screening targeting the mitochondrial transamidation pathway. Always consult the product datasheet for confirmed validated applications.

How should Recombinant Human GATB Protein be stored to maintain activity?

The protein should be stored at –80 °C for long-term use. Repeated freeze–thaw cycles should be avoided; it is advisable to aliquot the protein into single-use volumes upon first thaw. Refer to the Aladdin product datasheet for lot-specific storage buffer and stability information.

Is GATB related to any human diseases?

Defects in mitochondrial tRNA aminoacylation pathways, including those involving GatCAB complex subunits, have been associated with mitochondrial diseases that can affect energy-demanding tissues such as heart and skeletal muscle. Research into GATB variants is ongoing and Recombinant Human GATB Protein provides a tool for mechanistic studies.

What is the difference between GATB and other GatCAB subunits?

The GatCAB complex consists of three subunits: GatA (amidase), GatB (amidotransferase, encoded by GATB), and GatC (structural stabilizer). GatA hydrolyzes glutamine to generate ammonia, GatB uses this ammonia to amidate mischarged tRNAs, and GatC stabilizes the overall complex. Each subunit plays a distinct and non-redundant role.

References

1. Nagao A, Suzuki T, Katoh T, Sakaguchi Y, Suzuki T. Biogenesis of glutaminyl-mt tRNAGln in human mitochondria. Science. 2009;325(5938):individual pages not confirmed.
2. Sheppard K, Yuan J, Hohn MJ, Jester B, Bhatt DK, Bhatt D, Söll D. From one amino acid to another: tRNA-dependent amino acid biosynthesis. Nucleic Acids Res. 2008;36(6):1813-1825.
3. Aladdin Scientific. Recombinant Human GATB Protein, SKU rp372885. Product Datasheet.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.