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HAMAP rule MF_02003

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General rule information [?]

Accession MF_02003
Dates 5-DEC-2005 (Created)
1-JUN-2023 (Last updated, Version 25)
Name Ile_tRNA_synth_type2
Scope(s) Bacteria
Template(s) P56690 (SYI_THET8); P00956 (SYI_ECOLI); P41368 (SYI2_STAAU); P9WFV3 (SYI_MYCTU); Q8L1B1 (SYI2_PSEFL); [ Recover all ]
Triggered by HAMAP; MF_02003 (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=;
COFACTOR Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
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 2 subfamily.

Keywords [?]

Gene Ontology [?]

GO:0004822; Molecular function:isoleucine-tRNA ligase activity
GO:0005524; Molecular function:ATP binding
GO:0008270; Molecular function:zinc ion binding
GO:0006428; Biological process:isoleucyl-tRNA aminoacylation
GO:0005737; Cellular component:cytoplasm

Cross-references [?]

Pfam PF00133; tRNA-synt_1; 1;
NCBIfam TIGR00392; IleS; 1;

Features [?]

From: SYI_THET8 (P56690)
Key From To Description Tag Condition FTGroup
MOTIF 47 57 /note="'HIGH' region"
MOTIF 591 595 /note="'KMSKS' region"
BINDING 594 594 /ligand="ATP"

Additional information [?]

Size range 981-1213 amino acids
Related rules MF_02002
Fusion Nter: None Cter: None
Comments Some species have a second copy of IleRS in another subfamily (MF_02002). MYCTU, PSEFL and STAAU confer high-level resistance to the antibiotic mupirocin (pseudomonic acid A), an Ile-analog that competitively inhibits activation by Ile-tRNA synthetase, thus inhibiting protein biosynthesis. Shorter N-terminal in SACS2; sequence not included in alignment and not taken into account in size range.

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