Gene Ontology annotation through association of InterPro records with GO terms
Annotation inferences using phylogenetic trees
Electronic Gene Ontology annotations created by transferring manual GO annotations between related proteins based on shared sequence features
Electronic Gene Ontology annotations created by ARBA machine learning models
Combined Automated Annotation using Multiple IEA Methods
Substrate specificity for 4-thiouridine modification in Escherichia coli.
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s4U synthesis in E. coli needs IscS and ThiI. IscS moves sulfur from L-cysteine to ThiI; ThiI uses Mg-ATP to activate U8 of tRNA and transfers the sulfur to give s4U.
"IscS catalyzes sulfur transfer from l-cysteine to ThiI, which utilizes Mg-ATP to activate uridine 8 in tRNA and transfers sulfur to give s4U"
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The minimal ThiI substrate is a mini-helix of the stacked acceptor and T stems with a bulged loop of at least 4 nt whose first nucleotide is the target uridine.
"the minimum substrate for s4U modification is a mini-helix comprising the stacked acceptor and T stems containing an internal bulged region"
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Removing the 3'-terminal ACCA abolishes activity (<0.1%), and a single overhanging base restores it.
"An unmodified tRNA(Phe) transcript in which the 3'-terminal ACCA sequence is removed to give a blunt terminus has <0.1% activity"
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ThiI recognizes no primary sequence outside U8; secondary and tertiary structure alone restrict s4U to tRNA.
"outside of the modified U8, there is no primary sequence requirement for substrate recognition"
Evidence for the transfer of sulfane sulfur from IscS to ThiI during the in vitro biosynthesis of 4-thiouridine in Escherichia coli tRNA.
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Sulfane sulfur from IscS passes to ThiI and then to tRNA during in vitro s4U synthesis.
"the sulfane sulfur generated by IscS is transferred sequentially to ThiI and then to tRNA during the in vitro synthesis of s(4)U"
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ThiI binds unmodified tRNA(Phe).
"ThiI binds to unmodified E. coli tRNA(Phe)"
Evidence that ThiI, an enzyme shared between thiamin and 4-thiouridine biosynthesis, may be a sulfurtransferase that proceeds through a persulfide intermediate.
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ThiI has a C-terminal rhodanese-like domain whose Cys456 is essential for s4U synthesis in vitro and in vivo, consistent with a persulfide intermediate.
"the C456A ThiI is incapable of supporting generation of 4-thiouridine in tRNA both in vitro and in vivo"
The role of the cysteine residues of ThiI in the generation of 4-thiouridine in tRNA.
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Cys344 is essential, and a Cys344-Cys456 disulfide forms during turnover.
"We propose that Cys-344 forms a disulfide bond with Cys-456 during turnover"
Using genomic information to investigate the function of ThiI, an enzyme shared between thiamin and 4-thiouridine biosynthesis.
Deduced RNA binding mechanism of ThiI based on structural and binding analyses of a minimal RNA ligand.
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The ThiI N-terminal domain binds tRNA and the minimal TPHE39A ligand; the C-terminal domain does not.
"the N-domain can bind with both tRNA(Phe) and TPHE39A, whereas the C-domain cannot"
The rhodanese domain of ThiI is both necessary and sufficient for synthesis of the thiazole moiety of thiamine in Salmonella enterica.
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In Salmonella, the ThiI rhodanese domain alone supports thiazole synthesis, and residues needed for s4U synthesis are not needed for thiazole.
"the C-terminal rhodanese domain of ThiI was sufficient for thiazole synthesis in vivo"
Protein abundance profiling of the Escherichia coli cytosol.
Structural basis for Fe-S cluster assembly and tRNA thiolation mediated by IscS protein-protein interactions.
4-Thiouridine triggers both growth delay induced by near-ultraviolet light and photoprotection.
Identification of a gene involved in the generation of 4-thiouridine in tRNA.
Thiamin biosynthesis in Escherichia coli. Identification of ThiS thiocarboxylate as the immediate sulfur donor in the thiazole formation.
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Without thiI, ThiS lacks its C-terminal thiocarboxylate, the sulfur donor for thiazole.
"ThiS isolated from a thiI- strain does not contain this modification"
UniProtKB entry P77718 (THII_ECOLI)