Recombinant Tetraodon nigroviridis Glutamyl-tRNA (Gln) amidotransferase subunit C, mitochondrial (gatc)

Introduction to Glutamyl-tRNA (Gln) Amidotransferase Subunit C

The Recombinant Tetraodon nigroviridis Glutamyl-tRNA (Gln) amidotransferase subunit C, mitochondrial (gatc) is part of a crucial enzyme complex involved in the biosynthesis of glutaminyl-tRNA(Gln) in mitochondria. This process is essential for mitochondrial protein synthesis, as it ensures the correct charging of tRNA(Gln) with glutamine. The enzyme complex, known as GatCAB, consists of three subunits: GatA, GatB, and GatC, with GatC being the focus of this discussion.

Function and Importance of GatC

GatC, encoded by the GATC gene, plays a pivotal role in the indirect pathway of glutaminyl-tRNA(Gln) biosynthesis. In this pathway, mitochondrial glutamyl-tRNA synthetase first misaminoacylates tRNA(Gln) with glutamic acid, forming Glu-tRNA(Gln). The GatCAB complex then catalyzes the transamidation of Glu-tRNA(Gln) to Gln-tRNA(Gln), using free glutamine as an amide donor .

Key Functions:

• Transamidation Reaction: GatCAB complex facilitates the conversion of Glu-tRNA(Gln) to Gln-tRNA(Gln).

• Mitochondrial Localization: GatC is localized in the mitochondria, where it interacts with other subunits to form the functional GatCAB enzyme .

• Disease Association: Mutations in GATC and other GatCAB subunits have been linked to severe mitochondrial disorders, such as combined oxidative phosphorylation deficiencies and lethal cardiomyopathies .

3.1. Biochemical Studies

• Reconstitution of GatCAB Activity: Studies have successfully reconstituted the GatCAB complex in vitro, demonstrating its ability to convert Glu-tRNA(Gln) to Gln-tRNA(Gln) using recombinant subunits .

• Subcellular Localization: Experiments using EGFP-tagged proteins have confirmed that all GatCAB subunits, including GatC, are localized in mitochondria .

3.2. Disease Implications

• Mitochondrial Disorders: Pathogenic variants in GATC and other GatCAB subunits lead to impaired mitochondrial protein synthesis and severe metabolic disorders .

• Respiratory Chain Deficiencies: Defects in GatCAB function result in combined respiratory chain enzyme deficiencies, highlighting the critical role of this complex in maintaining mitochondrial function .

Table 1: Key Features of GatCAB Subunits

Table 2: Disease Associations

References GeneCards. GATC Gene. Biogenesis of glutaminyl-mt tRNAGln in human mitochondria. Pathogenic variants in glutamyl-tRNAGln amidotransferase subunits cause a lethal mitochondrial cardiomyopathy disorder. Dual-targeted tRNA-dependent amidotransferase ensures both mitochondrial and chloroplastic Gln-tRNAGln synthesis in plants. Glu-tRNAGln amidotransferase: A novel heterotrimeric enzyme. Gregarine single-cell transcriptomics reveals differential mitochondrial remodeling and adaptation in apicomplexans. Glutamyl-tRNAGln amidotransferase is essential for mammalian mitochondria. Synthesis and preliminary studies of 11C-labeled tetrahydro-1,7-naphthyridine-2-carboxamides for PET imaging of metabotropic glutamate receptor 2.