Characterization of the catalytic disulfide bond in <i>E. coli</i> 4‐thiouridine synthetase to elucidate its functional quaternary structure

Veerareddygari, Govardhan Reddy; Klusman, Thomas C.; Mueller, Eugene G.

doi:10.1002/pro.2965

Cited by 6 publications

(4 citation statements)

References 26 publications

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“…The first catalytic Cys (Cys456 in E. coli ThiI and Cys199 in E. coli MnmA) receives the persulfide from IscS, and subsequently the ThiI-and MnmApersulfide donate the sulfur to thiolate the activated C4 atom of U8 and C2 atom of U34, respectively (20,21). The second catalytic Cys (Cys344 in E. coli ThiI and Cys102 in E. coli MnmA) is proposed to form a disulfide bond with the first Cys, assisting sulfur release (20)(21)(22). The disulfide bond then needs to be reduced by a reductant before the next catalytic cycle.…”

mentioning

confidence: 99%

A [3Fe-4S] cluster is required for tRNA thiolation in archaea and eukaryotes

Liu

Vinyard

Reesbeck

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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The sulfur-containing nucleosides in transfer RNA (tRNAs) are present in all three domains of life; they have critical functions for accurate and efficient translation, such as tRNA structure stabilization and proper codon recognition. The tRNA modification enzymes ThiI (in bacteria and archaea) and Ncs6 (in archaea and eukaryotic cytosols) catalyze the formation of 4-thiouridine (s 4 U) and 2-thiouridine (s 2 U), respectively. The ThiI homologs were proposed to transfer sulfur via cysteine persulfide enzyme adducts, whereas the reaction mechanism of Ncs6 remains unknown. Here we show that ThiI from the archaeon Methanococcus maripaludis contains a [3Fe-4S] cluster that is essential for its tRNA thiolation activity. Furthermore, the archaeal and eukaryotic Ncs6 homologs as well as phosphoseryl-tRNA (Sep-tRNA):Cys-tRNA synthase (SepCysS), which catalyzes the Sep-tRNA to Cys-tRNA conversion in methanogens, also possess a [3Fe-4S] cluster similar to the methanogenic archaeal ThiI. These results suggest that the diverse tRNA thiolation processes in archaea and eukaryotic cytosols share a common mechanism dependent on a [3Fe-4S] cluster for sulfur transfer.iron-sulfur cluster | thionucleosides | tRNA modification | CTU1

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mentioning

confidence: 99%

A [3Fe-4S] cluster is required for tRNA thiolation in archaea and eukaryotes

Liu

Vinyard

Reesbeck

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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“…ThiI uses ATP to activate the C4 atom of U as an adenylated intermediate ( Figure 2 C). In E. coli , the sulfur atom of the persulfide formed at the catalytic center of IscS is transferred to Cys456 of the rhodanese-like domain (RLD) of ThiI, and the sulfur atom is then incorporated into tRNA via assistance from a second catalytic Cys344 ( Figure 2 C(1) and Figure 3 ) [ 79 , 80 , 81 , 82 ]. The substrate tRNA is mainly recognized by the N-terminal ferredoxin-like domain (NFLD) and the thiouridine synthase, methylase, and pseudouridine synthase (THUMP) domain of ThiI ( Figure 3 ) [ 83 ].…”

Section: Biosynthesis Pathways Of Sulfur Modification Of Rnamentioning

confidence: 99%

Biosynthesis and Degradation of Sulfur Modifications in tRNAs

Shigi

2021

IJMS

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Various sulfur-containing biomolecules include iron–sulfur clusters that act as cofactors for enzymes, sulfur-containing vitamins such as thiamin, and sulfur-modified nucleosides in RNA, in addition to methionine and cysteine in proteins. Sulfur-containing nucleosides are post-transcriptionally introduced into tRNA molecules, where they ensure precise codon recognition or stabilization of tRNA structure, thereby maintaining cellular proteome integrity. Modulating sulfur modification controls the translation efficiency of specific groups of genes, allowing organisms to adapt to specific environments. The biosynthesis of tRNA sulfur nucleosides involves elaborate ‘sulfur trafficking systems’ within cellular sulfur metabolism and ‘modification enzymes’ that incorporate sulfur atoms into tRNA. This review provides an up-to-date overview of advances in our knowledge of the mechanisms involved. It covers the functions, biosynthesis, and biodegradation of sulfur-containing nucleosides as well as the reaction mechanisms of biosynthetic enzymes catalyzed by the iron–sulfur clusters, and identification of enzymes involved in the de-modification of sulfur atoms of RNA. The mechanistic similarity of these opposite reactions is discussed. Mutations in genes related to these pathways can cause human diseases (e.g., cancer, diabetes, and mitochondrial diseases), emphasizing the importance of these pathways.

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“…Then the persulfidic sulfur from IscS is transferred to the first catalytic Cys456 of E. coli ThiI, forming a persulfide group on ThiI [44,61]. Subsequently, the second catalytic Cys344 forms a disulfide bond with Cys456 assisting the release of the sulfur from ThiI persulfide [62,63], which is then incorporated into the activated U8 forming s 4 U8. The in vitro reaction requires exogenous reductant (e.g., dithiothreitol) to break the Cys344–Cys456 disulfide bond before the next catalytic round [62], but the physiological reductant is unclear.…”

Section: Fe–s Cluster-dependent and Independent Trna Thiolation Prmentioning

confidence: 99%

Biosynthesis of Sulfur-Containing tRNA Modifications: A Comparison of Bacterial, Archaeal, and Eukaryotic Pathways

Čavužić

Liu

2017

Biomolecules

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Post-translational tRNA modifications have very broad diversity and are present in all domains of life. They are important for proper tRNA functions. In this review, we emphasize the recent advances on the biosynthesis of sulfur-containing tRNA nucleosides including the 2-thiouridine (s2U) derivatives, 4-thiouridine (s4U), 2-thiocytidine (s2C), and 2-methylthioadenosine (ms2A). Their biosynthetic pathways have two major types depending on the requirement of iron–sulfur (Fe–S) clusters. In all cases, the first step in bacteria and eukaryotes is to activate the sulfur atom of free l-cysteine by cysteine desulfurases, generating a persulfide (R-S-SH) group. In some archaea, a cysteine desulfurase is missing. The following steps of the bacterial s2U and s4U formation are Fe–S cluster independent, and the activated sulfur is transferred by persulfide-carrier proteins. By contrast, the biosynthesis of bacterial s2C and ms2A require Fe–S cluster dependent enzymes. A recent study shows that the archaeal s4U synthetase (ThiI) and the eukaryotic cytosolic 2-thiouridine synthetase (Ncs6) are Fe–S enzymes; this expands the role of Fe–S enzymes in tRNA thiolation to the Archaea and Eukarya domains. The detailed reaction mechanisms of Fe–S cluster depend s2U and s4U formation await further investigations.

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Characterization of the catalytic disulfide bond in E. coli 4‐thiouridine synthetase to elucidate its functional quaternary structure

Cited by 6 publications

References 26 publications

A [3Fe-4S] cluster is required for tRNA thiolation in archaea and eukaryotes

A [3Fe-4S] cluster is required for tRNA thiolation in archaea and eukaryotes

Biosynthesis and Degradation of Sulfur Modifications in tRNAs

Biosynthesis of Sulfur-Containing tRNA Modifications: A Comparison of Bacterial, Archaeal, and Eukaryotic Pathways

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