Structural and biochemical characterization of the 3'-5' tRNA splicing ligases

Publikationen als Autor:in / Herausgeber:in der Vetmeduni

Glatt, Sebastian

Abstrakt

In archaea and metazoa, tRNA exons are ligated by the RNA ligases RtcB and RTCB, respectively. The metazoan RTCB forms a stable complex with four additional subunits, DDX1, FAM98B, CGI99, and ASHWIN. The role and assembly these four components remain elusive. Furthermore, we lack structural information of how RNA substrates are recognized by 3'-5' tRNA ligases. Here, we use thiol-based chemical crosslinking to confirm the involvement of specific residues RtcB in RNA binding, and we present a cryo-EM structure the purified five-subunit Danio rerio tRNA ligase complex. The structure implies that the DDX1 helicase module is mobile and can modulate the activity of RTCB. Taken together, the presented results enhance our mechanistic understanding of RNA binding by 3'-5' tRNA splicing ligases and architecture of the metazoan tRNA ligase complex.

CC Lizenz

CCBY

DOI

10.1016/j.jbc.2025.108506

PubMed ID

MEDLINE:40220997