title: Biogenesis of 2-agmatinylcytidine catalyzed by the dual protein and RNA kinase TiaS.
abstract: The archaeal AUA-codon specific tRNA(Ile) contains 2-agmatinylcytidine (agm(2)C or agmatidine) at the anticodon wobble position (position 34). The formation of this essential modification is catalyzed by tRNA(Ile)-agm(2)C synthetase (TiaS) using agmatine and ATP as substrates. TiaS has a previously unknown catalytic domain, which we have named the Thr18-Cyt34 kinase domain (TCKD). Biochemical analyses of Archaeoglobus fulgidus TiaS and its mutants revealed that the TCKD first hydrolyzes ATP into AMP and pyrophosphate, then phosphorylates the C2 position of C34 with the γ-phosphate. Next, the amino group of agmatine attacks this position to release the phosphate and form agm(2)C. Notably, the TCKD also autophosphorylates the Thr18 of TiaS, which may be involved in agm(2)C formation. Thus, the unique kinase domain of TiaS catalyzes dual phosphorylation of protein and RNA substrates.
authors: Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo, Japan.
authors: Naohiro
authors: N
authors: Terasaka
authors: Satoshi
authors: S
authors: Kimura
authors: Takuo
authors: T
authors: Osawa
authors: Tomoyuki
authors: T
authors: Numata
authors: Tsutomu
authors: T
authors: Suzuki
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D000376:Agmatine / Q000737:chemistry* / Q000378:metabolism; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019611:Archaeoglobus fulgidus / Q000201:enzymology* / Q000235:genetics; D003562:Cytidine / Q000737:chemistry* / Q000378:metabolism; D007533:Isoleucine-tRNA Ligase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D015394:Molecular Structure; D017434:Protein Structure, Tertiary; D019642:RNA, Archaeal / Q000737:chemistry* / Q000378:metabolism; D012355:RNA, Transfer, Ile / Q000737:chemistry* / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D019642:RNA, Archaeal; D012355:RNA, Transfer, Ile; D003562:Cytidine; D000376:Agmatine; D000255:Adenosine Triphosphate; D007533:Isoleucine-tRNA Ligase