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HAMAP rule MF_02002

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General rule information [?]

Accession MF_02002
Dates 5-DEC-2005 (Created)
1-JUN-2023 (Last updated, Version 22)
Name Ile_tRNA_synth_type1
Templates P41972 (SYI1_STAAU); P00956 (SYI_ECOLI); P18330 (SYI1_PSEFL): [Recover all]

Propagated annotation [?]

Identifier, protein and gene names [?]

Protein name
RecName: Full=Isoleucine--tRNA ligase;
AltName: Full=Isoleucyl-tRNA synthetase;
Gene name

Comments [?]

Function Catalyzes the attachment of isoleucine to tRNA(Ile). As IleRS can inadvertently accommodate and process structurally similar amino acids such as valine, to avoid such errors it has two additional distinct tRNA(Ile)-dependent editing activities. One activity is designated as 'pretransfer' editing and involves the hydrolysis of activated Val-AMP. The other activity is designated 'posttransfer' editing and involves deacylation of mischarged Val-tRNA(Ile).
Catalytic activity RHEA:11060: ATP + L-isoleucine + tRNA(Ile) = AMP + diphosphate + L-isoleucyl-tRNA(Ile)
case <FTGroup:1>
Cofactor Zn(2+)
Note: Binds 1 zinc ion per subunit.
end case
Subunit Monomer.
Subcellular location Cytoplasm.
Domain IleRS has two distinct active sites: one for aminoacylation and one for editing. The misactivated valine is translocated from the active site to the editing site, which sterically excludes the correctly activated isoleucine. The single editing site contains two valyl binding pockets, one specific for each substrate (Val-AMP or Val-tRNA(Ile)).
Similarity Belongs to the class-I aminoacyl-tRNA synthetase family. IleS type 1 subfamily.

Keywords [?]

case <FT:9>
end case
case <FTGroup:1>
end case

Gene Ontology [?]

GO:0004822; Molecular function: isoleucine-tRNA ligase activity.
GO:0005524; Molecular function: ATP binding.
case <FTGroup:1>
GO:0008270; Molecular function: zinc ion binding.
end case
GO:0006428; Biological process: isoleucyl-tRNA aminoacylation.
GO:0005737; Cellular component: cytoplasm.

Cross-references [?]

Pfam PF00133; tRNA-synt_1; 1;
PF06827; zf-FPG_IleRS; 1;
NCBIfam TIGR00392; IleS; 1;

Features [?]

From: SYI1_STAAU (P41972)
Key     From     To       Description   Tag   Condition   FTGroup
MOTIF     57     67       'HIGH' region        
MOTIF     595     599       'KMSKS' region        
BINDING     886     886       /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105     C   1
BINDING     889     889       /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105     C   1
BINDING     906     906       /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105     C   1
BINDING     909     909       /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105     C   1
BINDING     554     554       /ligand="L-isoleucyl-5'-AMP" /ligand_id="ChEBI:CHEBI:178002     E  
BINDING     598     598       /ligand="ATP" /ligand_id="ChEBI:CHEBI:30616     K  
case <OC:Escherichia> or <OC:Shigella>
From: SYI_ECOLI (P00956)
MOD_RES     183     183       N6-acetyllysine     K  
end case

Additional information [?]

Size range 861-988 amino acids
Related rules MF_02003 (SYI)
Fusion None
Comments Some species have a second copy of IleRS in another subfamily (MF_02003).