HAMAP rule MF_02002

General rule information [?]

Accession	MF_02002
Dates	5-DEC-2005 (Created) 1-JUN-2023 (Last updated, Version 22)

Name	Ile_tRNA_synth_type1

Scope

Bacteria

Templates

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;
		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

case <FTGroup:1>

Cofactor

Zn(2+)
Note: Binds 1 zinc ion per subunit.

end case

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 1 subfamily.

Keywords [?]

case <FT:9>

Acetylation

end case

Aminoacyl-tRNA synthetase
ATP-binding
Cytoplasm
Ligase
Nucleotide-binding
Protein biosynthesis

case <FTGroup:1>

Metal-binding
Zinc

end case

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 [?]

PROSITE	PS00178; AA_TRNA_LIGASE_I; 1;
Pfam	PF00133; tRNA-synt_1; 1;
	PF06827; zf-FPG_IleRS; 1;
PRINTS	PR00984; TRNASYNTHILE; 1;
NCBIfam	TIGR00392; IleS; 1;

Features [?]

From: SYI1_STAAU (P41972)

Key From To Description Tag Condition FTGroup

MOTIF 57 67 'HIGH' region

MOTIF 595 599 'KMSKS' region

BINDING 886 886 /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105 C 1

BINDING 889 889 /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105 C 1

BINDING 906 906 /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105 C 1

BINDING 909 909 /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105 C 1

BINDING 554 554 /ligand="L-isoleucyl-5'-AMP" /ligand_id="ChEBI:CHEBI:178002 E

BINDING 598 598 /ligand="ATP" /ligand_id="ChEBI:CHEBI:30616 K

case <OC:Escherichia> or <OC:Shigella>

From: SYI_ECOLI (P00956)

MOD_RES 183 183 N6-acetyllysine K

end case

Additional information [?]

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

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