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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
Scope(s) Bacteria
Template(s) P41972 (SYI1_STAAU); P00956 (SYI_ECOLI); P18330 (SYI1_PSEFL); [ Recover all ]
Triggered by HAMAP; MF_02002 (Get profile general information and statistics)

Propagated annotation [?]

Identifier, protein and gene names [?]

Identifier SYI
Protein name RecName: Full=Isoleucine--tRNA ligase;
AltName: Full=Isoleucyl-tRNA synthetase;
Gene name Name=ileS;

Comments [?]

FUNCTIONCatalyzes 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 Reaction=ATP + L-isoleucine + tRNA(Ile) = AMP + diphosphate + L- isoleucyl-tRNA(Ile); Xref=Rhea:RHEA:11060, Rhea:RHEA-COMP:9666, Rhea:RHEA-COMP:9695, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58045, ChEBI:CHEBI:78442, ChEBI:CHEBI:78528, ChEBI:CHEBI:456215; EC=;
case <FTGroup:1>
COFACTOR Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Note=Binds 1 zinc ion per subunit.;
end case
DOMAINIleRS 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)).
SIMILARITYBelongs to the class-I aminoacyl-tRNA synthetase family. IleS type 1 subfamily.

Keywords [?]

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;
Pfam PF06827; zf-FPG_IleRS; 1;
NCBIfam TIGR00392; IleS; 1;

Features [?]

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

Additional information [?]

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

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