The [4Fe-4S] cluster of sulfurtransferase TtuA desulfurizes TtuB during tRNA modification in Thermus thermophilus.
Commun Biol
; 3(1): 168, 2020 04 07.
Article
em En
| MEDLINE
| ID: mdl-32265486
ABSTRACT
TtuA and TtuB are the sulfurtransferase and sulfur donor proteins, respectively, for biosynthesis of 2-thioribothymidine (s2T) at position 54 of transfer RNA (tRNA), which is responsible for adaptation to high temperature environments in Thermus thermophilus. The enzymatic activity of TtuA requires an iron-sulfur (Fe-S) cluster, by which a sulfur atom supplied by TtuB is transferred to the tRNA substrate. Here, we demonstrate that the Fe-S cluster directly receives sulfur from TtuB through its inherent coordination ability. TtuB forms a [4Fe-4S]-TtuB intermediate, but that sulfur is not immediately released from TtuB. Further desulfurization assays and mutation studies demonstrated that the release of sulfur from the thiocarboxylated C-terminus of TtuB is dependent on adenylation of the substrate tRNA, and the essential residue for TtuB desulfurization was identified. Based on these findings, the molecular mechanism of sulfur transfer from TtuB to Fe-S cluster is proposed.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Sulfurtransferases
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Tiouridina
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Proteínas de Bactérias
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RNA de Transferência
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Thermus thermophilus
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Proteínas Ferro-Enxofre
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article