Seryl-tRNA synthetase specificity for tRNASec in Bacterial Sec biosynthesis

Adriano de Freitas Fernandes; Vitor Hugo Balasco Serrão; Jéssica Fernandes Scortecci; Otavio Henrique Thiemann

doi:10.1016/j.bbapap.2020.140438

Seryl-tRNA synthetase specificity for tRNA^Sec in Bacterial Sec biosynthesis

Biochim Biophys Acta Proteins Proteom. 2020 Aug;1868(8):140438. doi: 10.1016/j.bbapap.2020.140438. Epub 2020 Apr 21.

Authors

Adriano de Freitas Fernandes¹, Vitor Hugo Balasco Serrão², Jéssica Fernandes Scortecci³, Otavio Henrique Thiemann⁴

Affiliations

¹ Physics Institute of Sao Carlos, University of Sao Paulo, Trabalhador São Carlense Av., 400. São Carlos, SP CEP 13566-590, Brazil.
² Physics Institute of Sao Carlos, University of Sao Paulo, Trabalhador São Carlense Av., 400. São Carlos, SP CEP 13566-590, Brazil; Laboratory Medicine & Pathobiology, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.
³ Physics Institute of Sao Carlos, University of Sao Paulo, Trabalhador São Carlense Av., 400. São Carlos, SP CEP 13566-590, Brazil; Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Science Mall, Vancouver, British Columbia V6T 1Z3, Canada.
⁴ Physics Institute of Sao Carlos, University of Sao Paulo, Trabalhador São Carlense Av., 400. São Carlos, SP CEP 13566-590, Brazil; Department of Genetics and Evolution, Federal University of São Carlos - UFSCar, 13565-905 São Carlos, 16 SP, Brazil. Electronic address: thiemann@ifsc.usp.br.

PMID: 32330624
DOI: 10.1016/j.bbapap.2020.140438

Abstract

tRNA synthetases are responsible for decoding the molecular information, from codons to amino acids. Seryl-tRNA synthetase (SerRS), besides the five isoacceptors of tRNA^Ser, recognizes tRNA^[Ser]Sec for the incorporation of selenocysteine (Sec, U) into selenoproteins. The selenocysteine synthesis pathway is known and is dependent on several protein-protein and protein-RNA interactions. Those interactions are not fully described, in particular, involving tRNA^[Ser]Sec and SerRS. Here we describe the molecular interactions between the Escherichia coli Seryl-tRNA synthetase (EcSerRS) and tRNA^[Ser]Sec in order to determine their specificity, selectivity and binding order, leading to tRNA aminoacylation. The dissociation constant of EcSerRS and tRNA^[Ser]Sec was determined as (126 ± 20) nM. We also demonstrate that EcSerRS binds initially to tRNA^[Ser]Sec in the presence of ATP for further recognition by E. coli selenocysteine synthetase (EcSelA) for Ser to Sec conversion. The proposed studies clarify the mechanism of tRNA^[Ser]Sec incorporation in Bacteria as well as of other domains of life.

Keywords: Protein-tRNA interaction; Selenocysteine; Seryl-tRNA synthetase; tRNA([Ser]Sec).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adenosine Triphosphate / metabolism
Binding Sites
Escherichia coli / genetics
Escherichia coli / metabolism*
Gene Expression Regulation, Bacterial*
Kinetics
Models, Molecular
Protein Binding
Protein Conformation, alpha-Helical
Protein Conformation, beta-Strand
Protein Interaction Domains and Motifs
RNA, Transfer, Amino Acid-Specific / genetics
RNA, Transfer, Amino Acid-Specific / metabolism*
RNA, Transfer, Cys / genetics
RNA, Transfer, Cys / metabolism*
Serine-tRNA Ligase / genetics
Serine-tRNA Ligase / metabolism*
Thermodynamics
Transfer RNA Aminoacylation / genetics
Transferases / genetics
Transferases / metabolism*

Substances

RNA, Transfer, Amino Acid-Specific
RNA, Transfer, Cys
tRNA, selenocysteine-
Adenosine Triphosphate
Transferases
selenium transferase
Serine-tRNA Ligase