Structural insights into tRNA recognition of the human FTSJ1-THADA complex

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• Transfer RNA (tRNA) requires post-transcriptional modifications in the anticodon loop for function.
• FTSJ1 protein mediates 2'-O-methylations (Nm32 or Nm34) in complex with THADA or WDR6.
• FTSJ1 mutations are linked to X-linked intellectual disability, highlighting its cellular importance.

Purpose of the Study:

• To elucidate the structural basis of the FTSJ1-THADA complex formation.
• To understand the mechanism of tRNA substrate recognition and binding by the FTSJ1-THADA complex.
• To clarify the role of this complex in Nm32 modification.

Main Methods:

• Cryo-electron microscopy (cryo-EM) was used to determine high-resolution structures.
• Biochemical analyses were performed to identify key residues involved in THADA-tRNA interactions.

Main Results:

• The high-resolution structure of the FTSJ1-THADA complex, with and without tRNA, was solved.
• FTSJ1 interacts with THADA via its C-terminal region, distinct from the FTSJ1-WDR6 complex.
• Key THADA residues mediating tRNA binding were identified, showing tRNA anchored within THADA.

Conclusions:

• The study reveals the unique structural mechanism of FTSJ1-THADA complex formation.
• It demonstrates how the complex specifically binds tRNA to perform Nm32 modification.
• These findings provide insights into tRNA modification pathways essential for accurate translation.