AC   MF_02002;
DC   Protein; auto
TR   HAMAP; MF_02002; -; 1; level=0
XX
Names: Ile_tRNA_synth_type1
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;
case <FTGroup:1>
CC   -!- COFACTOR:
CC       Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
CC       Note=Binds 1 zinc ion per subunit.;
end case
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 1 subfamily.
XX
DR   PROSITE; PS00178; AA_TRNA_LIGASE_I; 1; trigger=no
DR   Pfam; PF00133; tRNA-synt_1; 1; trigger=no
DR   Pfam; PF06827; zf-FPG_IleRS; 1; trigger=no
DR   PRINTS; PR00984; TRNASYNTHILE; 1; trigger=no
DR   NCBIfam; TIGR00392; IleS; 1; trigger=no
XX
case <FT:9>
KW   Acetylation
end case
KW   Aminoacyl-tRNA synthetase
KW   ATP-binding
KW   Cytoplasm
KW   Ligase
KW   Nucleotide-binding
KW   Protein biosynthesis
case <FTGroup:1>
KW   Metal-binding
KW   Zinc
end case
XX
GO   GO:0004822; F:isoleucine-tRNA ligase activity
GO   GO:0005524; F:ATP binding
case <FTGroup:1>
GO   GO:0008270; F:zinc ion binding
end case
GO   GO:0006428; P:isoleucyl-tRNA aminoacylation
GO   GO:0005737; C:cytoplasm
XX
FT   From: SYI1_STAAU (P41972)
FT   MOTIF           57..67
FT                   /note="'HIGH' region"
FT   MOTIF           595..599
FT                   /note="'KMSKS' region"
FT   BINDING         886
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT   Group: 1; Condition: C
FT   BINDING         889
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT   Group: 1; Condition: C
FT   BINDING         906
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT   Group: 1; Condition: C
FT   BINDING         909
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT   Group: 1; Condition: C
FT   BINDING         554
FT                   /ligand="L-isoleucyl-5'-AMP"
FT                   /ligand_id="ChEBI:CHEBI:178002"
FT   Condition: E
FT   BINDING         598
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT   Condition: K
FT   From: SYI_ECOLI (P00956)
case <OC:Escherichia> or <OC:Shigella>
FT   MOD_RES         183
FT                   /note="N6-acetyllysine"
FT   Condition: K
end case
XX
Size: 861-988;
Related: MF_02003;
Template: P41972; P00956; P18330;
Scope:
 Bacteria
Fusion:
 Nter: None
 Cter: None
Duplicate: in BURMA, BURPS
Plasmid: None
Comments: Some species have a second copy of IleRS in another subfamily (MF_02003).
XX
# Revision 1.22 2023/06/01
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