HAMAP

Accession	MF_02002
Dates	5-DEC-2005 (Created) 21-NOV-2011 (Last updated, Version 13)

Data class

Protein

Predictors

HAMAP; MF_02002; [distribution of match scores in UniProtKB];[seed alignment for MF_02002]

Names

Ile_tRNA_synth_type1

Identifier

SYI

Protein name

RecName: Full=Isoleucine--tRNA ligase; EC=6.1.1.5; AltName: Full=Isoleucyl-tRNA synthetase; Short=IleRS;

Gene name

ileS

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) (By similarity).

CATALYTIC ACTIVITY: ATP + L-isoleucine + tRNA(Ile) = AMP + diphosphate + L-isoleucyl-tRNA(Ile).

COFACTOR: Binds 1 zinc ion per subunit (By similarity).

SUBUNIT: Monomer (By similarity).

SUBCELLULAR LOCATION: Cytoplasm (By similarity).

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)) (By similarity).

SIMILARITY: Belongs to the class-I aminoacyl-tRNA synthetase family. IleS type 1 subfamily.

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

Acetylation.

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

Metal-binding, Zinc.

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.

From: SYI1_STAAU (P41972)
Key		From		To		Description		Condition		FTGroup
MOTIF		57		67		"HIGH" region
MOTIF		595		599		"KMSKS" region
METAL		886		886		Zinc (By similarity)		C		1
METAL		889		889		Zinc (By similarity)		C		1
METAL		906		906		Zinc (By similarity)		C		1
METAL		909		909		Zinc (By similarity)		C		1
BINDING		554		554		Aminoacyl-adenylate (By similarity)		E
BINDING		598		598		ATP (By similarity)		K

From: SYI_ECOLI (P00956)
Key		From		To		Description		Condition		FTGroup
MOD_RES		183		183		N6-acetyllysine (By similarity)		K

Size range:	861-988 amino acids
Related UniRules:	MF_02003 (SYI)
Template:	P41972 (SYI1_STAAU); P00956 (SYI_ECOLI); P18330 (SYI1_PSEFL): [Recover all]
Scope:	Bacteria
Fusion:	Nter: None; Cter: None
Duplicate:	in BURMA, BURPS
Plasmid encoded:	None
Comments:	Some species have a second copy of IleRS in another subfamily (MF_02003).