Annotation rule MF_00021
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General rule information [?]

Accession MF_00021
Dates 1-JUN-2001 (Created)
26-JUN-2017 (Last updated, Version 38)
Name ThiI
Scope Bacteria
Archaea
Templates P77718 (THII_ECOLI); P55913 (THII_SALTY); Q81KU0 (THII_BACAN): [Recover all]
Triggered by

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
THII
case <Feature:PS50206>
Protein name
RecName: Full=tRNA sulfurtransferase;
EC=2.8.1.4;
AltName: Full=Sulfur carrier protein ThiS sulfurtransferase;
AltName: Full=Thiamine biosynthesis protein ThiI;
AltName: Full=tRNA 4-thiouridine synthase;
end case
case not <Feature:PS50206>
Protein name
RecName: Full=Probable tRNA sulfurtransferase;
EC=2.8.1.4;
AltName: Full=Sulfur carrier protein ThiS sulfurtransferase;
AltName: Full=Thiamine biosynthesis protein ThiI;
AltName: Full=tRNA 4-thiouridine synthase;
end case
Gene name
thiI

Comments [?]

Function Catalyzes the ATP-dependent transfer of a sulfur to tRNA to produce 4-thiouridine in position 8 of tRNAs, which functions as a near-UV photosensor. Also catalyzes the transfer of sulfur to the sulfur carrier protein ThiS, forming ThiS-thiocarboxylate. This is a step in the synthesis of thiazole, in the thiamine biosynthesis pathway. The sulfur is donated as persulfide by IscS.
Catalytic activity ATP + [ThiI sulfur-carrier protein]-S-sulfanyl-L-cysteine + uracil in tRNA + 2 reduced ferredoxin [iron-sulfur] cluster = AMP + diphosphate + 4-thiouracil in tRNA + [ThiI sulfur-carrier protein]-L-cysteine + 2 oxidized ferredoxin [iron-sulfur] cluster.
[IscS]-SSH + [ThiS]-COAMP = [IscS]-SH + [ThiS]-COSH + AMP.
Pathway Cofactor biosynthesis; thiamine diphosphate biosynthesis.
Subcellular location Cytoplasm.
Similarity Belongs to the ThiI family.

Keywords [?]

case <Feature:PS51165>
RNA-binding
tRNA-binding
end case
ATP-binding
Cytoplasm
case <FT:7>
Disulfide bond
Redox-active center
end case
Nucleotide-binding
Thiamine biosynthesis
Transferase

Gene Ontology [?]

case <Feature:PS51165>
GO:0000049; Molecular function: tRNA binding.
end case
GO:0005524; Molecular function: ATP binding.
GO:0016783; Molecular function: sulfurtransferase activity.
GO:0009228; Biological process: thiamine biosynthetic process.
GO:0034227; Biological process: tRNA thio-modification.
GO:0005737; Cellular component: cytoplasm.

Cross-references [?]

PROSITE PS50206; RHODANESE_3; 0-1; trigger=PRU00173;
PS51165; THUMP; 1; trigger=PRU00529;
Pfam PF02568; ThiI; 1;
PF02926; THUMP; 1;
PF00581; Rhodanese; 1;
TIGRFAMs TIGR04271; ThiI_C_thiazole; 0-1;
TIGR00342; TIGR00342; 1;

Features [?]

From: THII_BACAN (Q81KU0)
Key     From     To       Description   Tag   Condition   FTGroup
NP_BIND     183     184       ATP     [LM]-x  
NP_BIND (Optional)     208     209       ATP     [HYNTS]-[FY]  
BINDING     265     265       ATP     [RK]  
BINDING     287     287       ATP; via amide nitrogen     G  
BINDING     296     296       ATP     Q  
case <Feature:PS50206>
From: THII_ECOLI (P77718)
ACT_SITE     456     456       Cysteine persulfide intermediate     C  
DISULFID     344     456       Redox-active     C-x*-C  
end case

Additional information [?]

Size range 368-486 amino acids
Related rules None
Fusion None
Comments Some proteins of this family do not possess a rhodanese domain, so there must be an external rhodanese-like partner involved. It is not known, and the reaction has not been characterized in this case.


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