Structure of a bacterial full-length type 2 isoleucyl-tRNA synthetase reveals the C-terminal tRNA-binding domain (CROSBI ID 710218)
Prilog sa skupa u zborniku | sažetak izlaganja sa skupa
Podaci o odgovornosti
Brkić, Alojzije ; Leibundgut, Marc ; Ban, Nenad ; Gruić Sovulj, Ita
engleski
Structure of a bacterial full-length type 2 isoleucyl-tRNA synthetase reveals the C-terminal tRNA-binding domain
IsoleucyltRNAsynthetases (IleRS) are universally conserved enzymes that covalently couple isoleucine to its cognate tRNAIle in a twostep aminoacylation reaction. These multidomain proteins consist of an aminoacylation domain, a proofreading domain, and a C-terminal anticodon binding domain involved in tRNA recognition. IleRSs cluster into two clades, IleRS1 and IleRS2, which differ in antibiotic resistance and the architecture of their Cterminal domain. The structure of the Cterminal anticodonbinding domain of IleRS1 is already known and entails three subdomains (SD): SD1 with helical bundle topology, SD2 consisting of four antiparallel βsheets and SD3 that is a αβ-fold with a zincbinding motif. [1] At the same time, the structure of the C terminal domain of IleRS2 remained unknown as only structures of truncated enzymes were reported. Here, for the first time, we present the structure of fulllength Bacillus megaterium IleRS2 with a completely resolved Cterminal domain at 2.3 Å resolution. The structure unveils that the C terminal domain of IleRS2 consists of three subdomains analogously to IleRS1. SD1 and SD2 in IleRS2 align structurally well with the corresponding subdomains in IleRS1. In contrast, SD3 lacks the zincbinding motif of IleRS1 SD3 and surprisingly, topologically resembles the SD2. Finally, the structure visualized a novel 75 amino acid long SD2 insertion, which is absent in IleRS1. We prepared a B. megaterium IleRS2 mutant with the SD2 insertion exchanged to a [Gly4Ser]2 loop. The mutant has a relatively modest 5fold decrease in aminoacylation rate as compared to the wildtype enzyme, which indicates that the SD2 insertion is important, but not essential for IleRS2 aminoacylation. The results thus open an intriguing question of whether SD2 of IleRS2 has a role outside of translation. References: [1] F. L. Silvian, J. Wang, A. T. Steitz, Science. 285 (1999) 1074–1077
isoleucyl-tRNA-sinthetase ; C-terminal domain ; structure
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
Podaci o prilogu
111-112.
2021.
objavljeno
Podaci o matičnoj publikaciji
Virtual symposium celebrating the 50th anniversary of the Protein Data Bank
Schiffer, Celia ; Berman, M. Helen ; Burley, K. Stephen ; Hoch, C. Jeffrey ; Kleywegt, J. Gerard ; Kurisu, Genji ; Markley, L. John ; Velankar, Sameer ; Zardecki, Christine
Podaci o skupu
A special symposium celebrating the 50th anniversary of the Protein Data Bank (PDB50)
poster
04.05.2021-05.05.2021
online