Dataset Information

On the mechanism and origin of isoleucyl-tRNA synthetase editing against norvaline

ABSTRACT: Aminoacyl-tRNA synthetases (aaRSs), the enzymes responsible for coupling tRNAs to their cognate amino acids, minimize translational errors by intrinsic hydrolytic editing. Here, we compared the propensity of norvaline (Nva), a linear amino acid not coded for protein synthesis, to the proteinogenic, branched valine (Val) to mistranslate isoleucine (Ile) in proteins. We show that in the synthetic site of isoleucyl-tRNA synthetase (IleRS), aminoacylation and pre-transfer editing with Nva and Val occur at similar rates. Post-transfer editing was, however, more efficient with Nva as IleRS misaminoacylates Nva-tRNAIle at slower rate than Val-tRNAIle. Accordingly, an Escherichia coli strain lacking IleRS post-transfer editing misincorporated Nva and Val in the proteome to a similar extent and at the same Ile positions. However, Nva mistranslation inflicted higher toxicity than Val, in agreement with IleRS post-transfer editing domain being optimized for hydrolysis of Nva-tRNAIle. Furthermore, we found that the evolutionary related IleRS, leucyl- and valyl-tRNA synthetases (I/L/VRSs), all efficiently hydrolyze Nva-tRNAs even when editing of Nva seems redundant. Thus, we hypothesize that editing of Nva-tRNAs had already existed in the last common ancestor of I/L/VRSs, and that the editing domain of I/L/VRSs had primarily evolved to prevent infiltration of Nva into modern proteins.

INSTRUMENT(S): LTQ Orbitrap Elite

ORGANISM(S): Escherichia Coli

SUBMITTER: Nicolas Nalpas

LAB HEAD: Boris Macek

PROVIDER: PXD011051 | Pride | 2019-01-28

REPOSITORIES: Pride

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Dataset's files

Source:

			Action	DRS
	20171123_MS_Ecoli_Tryp_Ita_Zg_IleRS_A12_on_MG1655_Rep1.raw	Raw
	20171123_MS_Ecoli_Tryp_Ita_Zg_IleRS_A22_on_MG1655_Rep2.raw	Raw
	20171123_MS_Ecoli_Tryp_Ita_Zg_IleRS_A32_on_MG1655_Rep3.raw	Raw
	20171123_MS_Ecoli_Tryp_Ita_Zg_IleRS_C12_on_MG1655_2mMVal_Rep1.raw	Raw
	20171123_MS_Ecoli_Tryp_Ita_Zg_IleRS_C22_on_MG1655_2mMVal_Rep2.raw	Raw

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Publications

On the Mechanism and Origin of Isoleucyl-tRNA Synthetase Editing against Norvaline.

Bilus Mirna M Semanjski Maja M Mocibob Marko M Zivkovic Igor I Cvetesic Nevena N Tawfik Dan S DS Toth-Petroczy Agnes A Macek Boris B Gruic-Sovulj Ita I

Journal of molecular biology 20190131 6

Aminoacyl-tRNA synthetases (aaRSs), the enzymes responsible for coupling tRNAs to their cognate amino acids, minimize translational errors by intrinsic hydrolytic editing. Here, we compared norvaline (Nva), a linear amino acid not coded for protein synthesis, to the proteinogenic, branched valine (Val) in their propensity to mistranslate isoleucine (Ile) in proteins. We show that in the synthetic site of isoleucyl-tRNA synthetase (IleRS), Nva and Val are activated and transferred to tRNA at simi ...[more]

PMID: 30711543

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