Literature summary for 6.1.1.4 extracted from

Zhou, X.L.; Wang, E.D.
Two tyrosine residues outside the editing active site in Giardia lamblia leucyl-tRNA synthetase are essential for the post-transfer editing (2009), Biochem. Biophys. Res. Commun., 386, 510-515.

Search for more literature for 6.1.1.4

Protein Variants

Protein Variants	Comment	Organism
Y515A	109% of wild-type activity	Giardia intestinalis
Y515E	42% of wild-type activity	Giardia intestinalis
Y515K	51% of wild-type activity	Giardia intestinalis
Y520A	68% of wild-type activity	Giardia intestinalis
Y520E	41% of wild-type activity	Giardia intestinalis
Y520H	46% of wild-type activity	Giardia intestinalis

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.0054	-	L-leucine	mutant Y515A, pH 8.2, 45°C	Giardia intestinalis
0.0054	-	L-leucine	mutant Y515E, pH 8.2, 45°C	Giardia intestinalis
0.0054	-	L-leucine	mutant Y520H, pH 8.2, 45°C	Giardia intestinalis
0.006	-	L-leucine	mutant Y520A, pH 8.2, 45°C	Giardia intestinalis
0.0061	-	L-leucine	wild-type, pH 8.2, 45°C	Giardia intestinalis
0.0077	-	L-leucine	mutant Y520E, pH 8.2, 45°C	Giardia intestinalis
0.008	-	L-leucine	mutant Y515K, pH 8.2, 45°C	Giardia intestinalis
0.0092	-	L-isoleucyl-tRNALeu	wild-type, pH 7.5, 37°C	Giardia intestinalis
0.0122	-	L-isoleucyl-tRNALeu	mutant Y515A, pH 7.5, 37°C	Giardia intestinalis
0.0147	-	L-isoleucyl-tRNALeu	mutant Y520H, pH 7.5, 37°C	Giardia intestinalis
0.0173	-	L-isoleucyl-tRNALeu	mutant Y520A, pH 7.5, 37°C	Giardia intestinalis

Organism

Organism	UniProt	Comment	Textmining
Giardia intestinalis	-	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ATP + L-leucine + tRNALeu	-	Giardia intestinalis	AMP + diphosphate + L-leucyl-tRNALeu	-	?
L-isoleucyl-tRNALeu + H2O	-	Giardia intestinalis	t-RNALeu + isoleucine	editing activity	?
additional information	residues Y515 and Y520 outside the editing active site of CP1 domain of Giardia lamblia LeuRS are crucial for post-transfer editing by influencing the binding affinity with mischarged tRNALeu	Giardia intestinalis	?	-	?

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
0.19	-	L-isoleucyl-tRNALeu	mutant Y515A, pH 7.5, 37°C	Giardia intestinalis
0.48	-	L-isoleucyl-tRNALeu	mutant Y520A, pH 7.5, 37°C	Giardia intestinalis
0.93	-	L-isoleucyl-tRNALeu	mutant Y520H, pH 7.5, 37°C	Giardia intestinalis
1	-	L-leucine	mutant Y515E, pH 8.2, 45°C	Giardia intestinalis
1.1	-	L-leucine	mutant Y520H, pH 8.2, 45°C	Giardia intestinalis
1.4	-	L-leucine	mutant Y520E, pH 8.2, 45°C	Giardia intestinalis
1.52	-	L-isoleucyl-tRNALeu	wild-type, pH 7.5, 37°C	Giardia intestinalis
1.8	-	L-leucine	mutant Y515K, pH 8.2, 45°C	Giardia intestinalis
1.8	-	L-leucine	mutant Y520A, pH 8.2, 45°C	Giardia intestinalis
2.6	-	L-leucine	mutant Y515A, pH 8.2, 45°C	Giardia intestinalis
2.7	-	L-leucine	wild-type, pH 8.2, 45°C	Giardia intestinalis

kcat/KM [mM/s]

kcat/KM Value [1/mMs^-1]	kcat/KM Value Maximum [1/mMs^-1]	Substrate	Comment	Organism	Structure
0.016	-	L-isoleucyl-tRNALeu	mutant Y515A, pH 7.5, 37°C	Giardia intestinalis
0.028	-	L-isoleucyl-tRNALeu	mutant Y520A, pH 7.5, 37°C	Giardia intestinalis
0.063	-	L-isoleucyl-tRNALeu	mutant Y520H, pH 7.5, 37°C	Giardia intestinalis
0.165	-	L-isoleucyl-tRNALeu	wild-type, pH 7.5, 37°C	Giardia intestinalis
0.181	-	L-leucine	mutant Y520E, pH 8.2, 45°C	Giardia intestinalis
0.185	-	L-leucine	mutant Y515E, pH 8.2, 45°C	Giardia intestinalis
0.203	-	L-leucine	mutant Y520H, pH 8.2, 45°C	Giardia intestinalis
0.225	-	L-leucine	mutant Y515K, pH 8.2, 45°C	Giardia intestinalis
0.3	-	L-leucine	mutant Y520A, pH 8.2, 45°C	Giardia intestinalis
0.442	-	L-leucine	wild-type, pH 8.2, 45°C	Giardia intestinalis
0.481	-	L-leucine	mutant Y515A, pH 8.2, 45°C	Giardia intestinalis

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Release 2023.1 (January 2023)