The universal YrdC/Sua5 family is required for the formation of threonylcarbamoyladenosine in tRNA

• Published in: Nucleic acids research Vol. 37; no. 9; pp. 2894 - 2909
• Main Authors: El Yacoubi, Basma, Lyons, Benjamin, Cruz, Yulien, Reddy, Robert, Nordin, Brian, Agnelli, Fabio, Williamson, James R., Schimmel, Paul, Swairjo, Manal A., de Crécy-Lagard, Valérie
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.05.2009; Oxford Publishing Limited (England)
• Subjects: Adenosine - analogs & derivatives; Adenosine - biosynthesis; Adenosine Triphosphate - metabolism; Amino Acid Sequence; DNA-Binding Proteins - genetics; Escherichia coli; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Genes, Essential; Genomics; Molecular Sequence Data; RNA; RNA, Transfer - chemistry; RNA, Transfer - metabolism; RNA, Transfer, Thr - chemistry; RNA, Transfer, Thr - metabolism; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins - genetics
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/gkp152

Threonylcarbamoyladenosine (t6A) is a universal modification found at position 37 of ANN decoding tRNAs, which imparts a unique structure to the anticodon loop enhancing its binding to ribosomes in vitro. Using a combination of bioinformatic, genetic, structural and biochemical approaches, the universal protein family YrdC/Sua5 (COG0009) was shown to be involved in the biosynthesis of this hypermodified base. Contradictory reports on the essentiality of both the yrdC wild-type gene of Escherichia coli and the SUA5 wild-type gene of Saccharomyces cerevisiae led us to reconstruct null alleles for both genes and prove that yrdC is essential in E. coli, whereas SUA5 is dispensable in yeast but results in severe growth phenotypes. Structural and biochemical analyses revealed that the E. coli YrdC protein binds ATP and preferentially binds RNAThr lacking only the t6A modification. This work lays the foundation for elucidating the function of a protein family found in every sequenced genome to date and understanding the role of t6A in vivo.