EC 6 Ligases

NEW ENTRIES

EC 6.2.1.33

Recommended name: 4-chlorobenzoate-CoA ligase

Reaction: 4-chlorobenzoate + CoA + ATP = 4-chlorobenzoyl-CoA + AMP + diphosphate

Systematic name: 4-chlorobenzoate:CoA ligase

Comments: requires Mg2+. This enzyme is part of the bacterial 2,4-dichlorobenzoate degradation pathway.

References:

1. Dunaway-Mariano, D., Babbitt, P.C. On the origins and functions of the enzymes of the 4-chlorobenzoate to 4-hydroxybenzoate converting pathway. Biodegradation 5 (1994) 259-276. [PMID: 7765837]

2. Loffler, F., Muller, R., Lingens, F. Purification and properties of 4-halobenzoate-coenzyme A ligase from Pseudomonas sp. CBS3. Biol. Chem. Hoppe-Seyler 373 (1992) 1001-1007. [PMID: 1418673]

3. Chang, K.H., Liang, P.H., Beck, W., Scholten, J.D., Dunaway-Mariano, D. Isolation and characterization of the three polypeptide components of 4-chlorobenzoate dehalogenase from Pseudomonas sp. strain CBS-3. Biochemistry 31 (1992) 5605-5610. [PMID: 1610806]

EC 6.3.1.8

Recommended name: glutathionylspermidine synthase

Reaction: [gamma]-L-glutamyl-L-cysteinyl-glycine + spermidine + ATP = N1-([gamma]-L-glutamyl-L-cysteinyl-glycyl)-spermidine + ADP + phosphate

(Glutathione + spermidine + ATP = glutathionylspermidine + ADP + phosphate)

Other name(s): glutathione:spermidine ligase (ADP-forming)

Systematic name: spermidine is numbered so that atom N-1 is in the amino group of the aminopropyl part of the molecule. [gamma]-L-Glutamyl-L-cysteinyl-glycine:spermidine ligase (ADP-forming)

Comments: Requires magnesium ions. Involved in the synthesis of trypanothione in trypanosomatids. The enzyme from E. coli is bifunctional and also catalyses the glutathionylspermidine amidase (EC 3.5.1.78) reaction, resulting in a net hydrolysis of ATP.

References:

1. Smith, K., Nadeau, K., Bradley, M., Walsh, C.T., Fairlamb, A.H. Purification of glutathionylspermidine and trypanothione synthase from Crithidia fasciculata. Protein Sci. 1 (1992) 874-883. [PMID: 1304372]

2. Bollinger, J.M., Kwon, D.S., Huisman, G.W., Kolter, R., Walsh, C.T. Glutathionylspermidine metabolism in E. coli. Purification, cloning, overproduction and characterization of a bifunctional glutathionyl spermidine synthetase/amidase. J. Biol. Chem. 270 (1995) 14031-14041. [PMID: 7775463]

EC 6.3.1.9

Recommended name: trypanothione synthase

Reaction: [gamma]-L-glutamyl-L-cysteinyl-glycine + N1-([gamma]-L-glutamyl-L-cysteinyl-glycyl)-spermidie + ATP = N1,N8-bis-([gamma]-L-glutamyl-L-csteinyl-glycyl)-spermidine + ADP + phosphate

(glutathione + glutathionylspermidine + ATP = N1,N8-bis-(glutathionyl)spermidine + ADP + phosphate)

Systematic name: glutathionylspermidine:glutathione ligase (ADP-forming)

Comments: involved in the synthesis of trypanothione in trypanosomatids

References:

1. Smith, K., Nadeau, K., Bradley, M., Walsh, C.T., Fairlamb, A.H. Purification of glutathionyl spermidine and trypanothione synthase from Crithidia fasciculata. Protein Sci. 1 (1992) 874-883. [PMID: 1304372]

EC 6.3.2.25

Recommended name: tubulin-tyrosine ligase

Reaction: ATP + detyrosinated [alpha]-tubulin + L-tyrosine = [alpha]-tubulin + ADP + phosphate

Systematic name: [alpha]-tubulin-L-tyrosine ligase (ADP-forming)

Comments: L-Tyrosine is linked via a peptide bond to the C-terminus of de-tyrosinated [alpha]-tubulin (des-Tyr[omega]-[alpha]-tubulin). The enzyme is highly specific for [alpha]-tubulin and moderately specific for ATP and L-tyrosine. L-Phenylalanine and 3,4-dihydroxy-L-phenylalanine are transferred but with higher Km values.

References:

1. Wehland, J., Schröder, H.C., Weber, K. Isolation and purification of tubulin-tyrosine ligase. Methods Enzymol. 134 (1986) 170-179. [PMID: 3821560]

2. Rudiger, M., Wehland, J., Weber, K. The carboxy-terminal peptide of detyrosinated alpha tubulin provides a minimal system to study the substrate specificity of tubulin-tyrosine ligase. Eur. J. Biochem. 220 (1994) 309-320. [PMID: 7510228]


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