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HAMAP rule MF_01850

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General rule information [?]

Accession MF_01850
Dates 15-JUL-2008 (Created)
17-FEB-2023 (Last updated, Version 16)
Name TtcA
Bacteria; Bacteroidota
Bacteria; Acaryochloris
Bacteria; Deinococcota
Bacteria; Pseudomonadota
Templates P76055 (TTCA_ECOLI); Q8ZP88 (TTCA_SALTY): [Recover all]

Propagated annotation [?]

Identifier, protein and gene names [?]

Protein name
RecName: Full=tRNA-cytidine(32) 2-sulfurtransferase;
EC 2.8.1.-;
AltName: Full=Two-thiocytidine biosynthesis protein A;
AltName: Full=tRNA 2-thiocytidine biosynthesis protein TtcA;
Gene name

Comments [?]

Function Catalyzes the ATP-dependent 2-thiolation of cytidine in position 32 of tRNA, to form 2-thiocytidine (s(2)C32). The sulfur atoms are provided by the cysteine/cysteine desulfurase (IscS) system.
Catalytic activity RHEA:57048: AH2 + ATP + cytidine(32) in tRNA + S-sulfanyl-L-cysteinyl-[cysteine desulfurase] = 2-thiocytidine(32) in tRNA + A + AMP + diphosphate + H(+) + L-cysteinyl-[cysteine desulfurase]
PhysiologicalDirection=left-to-right (RHEA:57049)
Cofactor [4Fe-4S] cluster
Note: Binds 1 [4Fe-4S] cluster per subunit. The cluster is chelated by three Cys residues, the fourth Fe has a free coordination site that may bind a sulfur atom transferred from the persulfide of IscS
Pathway tRNA modification.
Subunit Homodimer.
Subcellular location Cytoplasm.
Miscellaneous The thiolation reaction likely consists of two steps: a first activation step by ATP to form an adenylated intermediate of the target base of tRNA, and a second nucleophilic substitution step of the sulfur (S) atom supplied by the hydrosulfide attached to the Fe-S cluster.
Similarity Belongs to the TtcA family.

Keywords [?]

Gene Ontology [?]

GO:0000287; Molecular function: magnesium ion binding.
GO:0005524; Molecular function: ATP binding.
GO:0016783; Molecular function: sulfurtransferase activity.
GO:0051539; Molecular function: 4 iron, 4 sulfur cluster binding.
GO:0034227; Biological process: tRNA thio-modification.
GO:0005737; Cellular component: cytoplasm.

Cross-references [?]

Pfam PF01171; ATP_bind_3; 1;
PIRSF PIRSF004976; ATPase_YdaO; 1;

Features [?]

From: TTCA_ECOLI (P76055)
Key     From     To       Description   Tag   Condition   FTGroup
MOTIF     47     52       PP-loop motif     S-G-G-K-D-S  
BINDING     122     122       /ligand="[4Fe-4S] cluster" /ligand_id="ChEBI:CHEBI:49883     C   1
BINDING     125     125       /ligand="[4Fe-4S] cluster" /ligand_id="ChEBI:CHEBI:49883     C   1
BINDING     213     213       /ligand="[4Fe-4S] cluster" /ligand_id="ChEBI:CHEBI:49883     C   1

Additional information [?]

Size range 251-381 amino acids
Related rules None
Fusion None