24BT

Crystal structure of Peptidyl-tRNA Hydrolase 2 from Candidatus Lokiarchaeum sp. GC14_75

Summary for 24BT

• Entry DOI: 10.2210/pdb24bt/pdb
• Descriptor: peptidyl-tRNA hydrolase (2 entities in total)
• Functional Keywords: peptidyl-trna hydrolase, translation, hydrolase
• Biological source: Candidatus Lokiarchaeum sp. GC14_75
• Total number of polymer chains: 3
• Total formula weight: 43049.34

Authors

Kawashima, A.K.,Ito, K.I. (deposition date: 2026-02-27, release date: 2026-09-02, Last modification date: 2026-09-09)

Primary citation

Kawashima, A.,Ito, K.
Structural and functional analysis of peptidyl-tRNA hydrolase 2 from Candidatus Lokiarchaeum sp. GC14_75.
Acta Crystallogr.,Sect.F, 82:320-328, 2026

PubMed Abstract: Peptidyl-tRNA hydrolase (Pth2) hydrolyzes peptidyl-tRNA, an immature product of aborted translation, into peptide and tRNA, thereby maintaining cellular protein synthesis through peptide release and tRNA recycling. Here, we present the crystal structure of Pth2 from Candidatus Lokiarchaeum sp. GC14_75 (LokiPth2) at 2.12 Å resolution. This is the first structure of Pth2 from a lineage within Promethearchaeati, a kingdom of archaea closely related to eukaryotes. The structure reveals that LokiPth2 forms a homodimer and closely resembles Pth2 structures from other species. However, LokiPth2 exhibits two prominent structural differences: a short helix around the catalytic center, which is absent in other Pth2s, and a distinct orientation of the C-terminal helix. Detailed comparative structural analysis suggests that these regions may regulate enzymatic activity and substrate binding, respectively. Furthermore, the corresponding regions in other Pth2s also exhibit high flexibility, suggesting that similar mechanisms may be conserved among Pth2s. To gain insights into the growth environment of Candidatus Lokiarchaeum sp. GC14_75, we assess the optimal temperature for the catalytic reaction of LokiPth2, which suggests that Candidatus Lokiarchaeum sp. GC14_75 inhabits moderately thermophilic environments.

PubMed: 42626907
DOI: 10.1107/S2053230X26008423

Experimental method

X-RAY DIFFRACTION (2.12 Å)