9R3W

Fungal tRNA ligase Trl1-LIG-KIN

Summary for 9R3W

• Entry DOI: 10.2210/pdb9r3w/pdb
• Descriptor: tRNA ligase, GUANOSINE-5'-DIPHOSPHATE, DIPHOSPHOMETHYLPHOSPHONIC ACID ADENOSYL ESTER, ... (5 entities in total)
• Functional Keywords: trna ligase, polynucleotide kinase, trna splicing, adenylyltransferase, ligase
• Biological source: Thermochaetoides thermophila
• Total number of polymer chains: 1
• Total formula weight: 71952.50

Authors

Peschek, J.,Koehler, S. (deposition date: 2025-05-06, release date: 2025-10-08)

Primary citation

Kohler, S.,Peschek, J.
Interdomain assembly between the fungal tRNA ligase adenylyltransferase and kinase domain.
Rna, 2025

PubMed Abstract: Trl1-type ligases play an essential role in fungi and plants during the non-conventional tRNA splicing as well as the unfolded protein response. The tripartite enzyme consists of an N-terminal adenylyltransferase domain (LIG), a central polynucleotide kinase domain (KIN) and a C-terminal cyclic phosphodiesterase domain (CPD). The Trl1-mediated reaction can be divided into two steps: (1) RNA end modification by the KIN and CPD domains, and (2) the adenylyltransferase reaction catalyzed by the LIG domain resulting in the phosphodiester bond formation. Due to its absence in humans, Trl1 is often discussed as potential target for antifungal therapy. To date structural information on the full-length Trl1 are missing. Several crystal structures of the individual LIG and KIN as well as a KIN-CPD construct have been solved, thereby elucidating the fold of the individual domains, their cofactor and substrate binding. Here, we provide the missing crystal structure of the two-domain LIG-KIN construct from the thermophilic fungus Chaetomium thermophilum revealing the interdomain assembly and interface. Based on our structure and complementing AlphaFold3 predictions, we further propose a model with implications for interdomain RNA substrate transfer.

PubMed: 40983467
DOI: 10.1261/rna.080592.125

Experimental method

X-RAY DIFFRACTION (1.89 Å)