AC   MF_02003;
DC   Protein; auto
TR   HAMAP; MF_02003; -; 1; level=0
XX
Names: Ile_tRNA_synth_type2
XX
ID   SYI
DE   RecName: Full=Isoleucine--tRNA ligase;
DE            EC=6.1.1.5;
DE   AltName: Full=Isoleucyl-tRNA synthetase;
DE            Short=IleRS;
GN   Name=ileS;
XX
CC   -!- FUNCTION: Catalyzes the attachment of isoleucine to tRNA(Ile). As IleRS
CC       can inadvertently accommodate and process structurally similar amino
CC       acids such as valine, to avoid such errors it has two additional
CC       distinct tRNA(Ile)-dependent editing activities. One activity is
CC       designated as 'pretransfer' editing and involves the hydrolysis of
CC       activated Val-AMP. The other activity is designated 'posttransfer'
CC       editing and involves deacylation of mischarged Val-tRNA(Ile).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=ATP + L-isoleucine + tRNA(Ile) = AMP + diphosphate + L-
CC         isoleucyl-tRNA(Ile); Xref=Rhea:RHEA:11060, Rhea:RHEA-COMP:9666,
CC         Rhea:RHEA-COMP:9695, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019,
CC         ChEBI:CHEBI:58045, ChEBI:CHEBI:78442, ChEBI:CHEBI:78528,
CC         ChEBI:CHEBI:456215; EC=6.1.1.5;
CC   -!- COFACTOR:
CC       Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
CC   -!- SUBUNIT: Monomer.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm.
CC   -!- DOMAIN: IleRS has two distinct active sites: one for aminoacylation and
CC       one for editing. The misactivated valine is translocated from the
CC       active site to the editing site, which sterically excludes the
CC       correctly activated isoleucine. The single editing site contains two
CC       valyl binding pockets, one specific for each substrate (Val-AMP or Val-
CC       tRNA(Ile)).
CC   -!- SIMILARITY: Belongs to the class-I aminoacyl-tRNA synthetase family.
CC       IleS type 2 subfamily.
XX
DR   PROSITE; PS00178; AA_TRNA_LIGASE_I; 1; trigger=no
DR   Pfam; PF00133; tRNA-synt_1; 1; trigger=no
DR   PRINTS; PR00984; TRNASYNTHILE; 1; trigger=no
DR   NCBIfam; TIGR00392; IleS; 1; trigger=no
XX
KW   Cytoplasm
KW   Aminoacyl-tRNA synthetase
KW   ATP-binding
KW   Ligase
KW   Nucleotide-binding
KW   Protein biosynthesis
KW   Metal-binding
KW   Zinc
XX
GO   GO:0004822; F:isoleucine-tRNA ligase activity
GO   GO:0005524; F:ATP binding
GO   GO:0008270; F:zinc ion binding
GO   GO:0006428; P:isoleucyl-tRNA aminoacylation
GO   GO:0005737; C:cytoplasm
XX
FT   From: SYI_THET8 (P56690)
FT   MOTIF           47..57
FT                   /note="'HIGH' region"
FT   MOTIF           591..595
FT                   /note="'KMSKS' region"
FT   BINDING         594
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT   Condition: K
XX
Size: 981-1213;
Related: MF_02002;
Template: P56690; P00956; P41368; P9WFV3; Q8L1B1;
Scope:
 Bacteria
 Archaea
Fusion:
 Nter: None
 Cter: None
Duplicate: None
Plasmid: in STAAU
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.
XX
# Revision 1.25 2023/06/01
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