A role for the universal Kae1/Qri7/YgjD (COG0533) family in tRNA modification.

Basma El Yacoubi , Isabelle Hatin (1) , Christopher Deutsch , Tamer Kahveci , Jean-Pierre Rousset (1) , Dirk Iwata-Reuyl , Alexey G Murzin , Valérie de Crécy-Lagard

1 IGM - Institut de génétique et microbiologie [Orsay]

The YgjD/Kae1 family (COG0533) has been on the top-10 list of universally conserved proteins of unknown function for over 5 years. It has been linked to DNA maintenance in bacteria and mitochondria and transcription regulation and telomere homeostasis in eukaryotes, but its actual function has never been found. Based on a comparative genomic and structural analysis, we predicted this family was involved in the biosynthesis of N(6)-threonylcarbamoyl adenosine, a universal modification found at position 37 of tRNAs decoding ANN codons. This was confirmed as a yeast mutant lacking Kae1 is devoid of t(6)A. t(6)A(-) strains were also used to reveal that t(6)A has a critical role in initiation codon restriction to AUG and in restricting frameshifting at tandem ANN codons. We also showed that YaeZ, a YgjD paralog, is required for YgjD function in vivo in bacteria. This work lays the foundation for understanding the pleiotropic role of this universal protein family.

Domaines: Biochimie, Biologie Moléculaire; Microbiologie et Parasitologie

Basma El Yacoubi, Isabelle Hatin, Christopher Deutsch, Tamer Kahveci, Jean-Pierre Rousset, et al.. A role for the universal Kae1/Qri7/YgjD (COG0533) family in tRNA modification.. EMBO Journal, 2011, 30 (5), pp.882-93. ⟨10.1038/emboj.2010.363⟩. ⟨hal-00593551⟩