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Annotation rule MF_02003
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General rule information [?]

Accession MF_02003
Dates 5-DEC-2005 (Created)
20-NOV-2019 (Last updated, Version 22)
Name Ile_tRNA_synth_type2
Scope
Bacteria
Archaea
Templates P56690 (SYI_THET8); P00956 (SYI_ECOLI); P41368 (SYI2_STAAU); P9WFV3 (SYI_MYCTU); Q8L1B1 (SYI2_PSEFL): [Recover all]

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
SYI
Protein name
RecName: Full=Isoleucine--tRNA ligase;
EC 6.1.1.5;
AltName: Full=Isoleucyl-tRNA synthetase;
Short=IleRS;
Gene name
ileS

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)
EC 6.1.1.5
Cofactor Zn(2+)
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 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 [?]

PROSITE PS00178; AA_TRNA_LIGASE_I; 1;
Pfam PF00133; tRNA-synt_1; 1;
PRINTS PR00984; TRNASYNTHILE; 1;
TIGRFAMs TIGR00392; IleS; 1;

Features [?]

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

Additional information [?]

Size range 981-1213 amino acids
Related rules MF_02002 (SYI)
Fusion 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.