Literature summary for 2.4.1.90 extracted from

Ramakrishnan, B.; Boeggeman, E.; Qasba, P.K.
Effect of Met344His mutation on the conformational dynamics of bovine beta-1,4-galactosyltransferase: crystal structure of the Met344His mutant in complex with chitobiose (2004), Biochemistry, 43, 12513-12522.

Crystallization (Commentary)

Crystallization (Comment)	Organism
M344H mutant enzyme complexed with UDP-Gal and Mn2+ or Mg2+, hanging drop vapour diffusion method, 30 mg/ml protein in solution with 17 mM UDP-Gal, and 17 mM MgCl2 or MnCl2, precipitated by 10% v/v dioxane, 100 mM MES-NaOH, pH 6.5, and 2.0M ammonium sulfate, room temperature, X-ray diffraction structure determination and analysis at 2.3 A resolution, determination of conformation stereochemistry, modeling	Bos taurus

Crystallization (Comment)

Organism

M344H mutant enzyme complexed with UDP-Gal and Mn2+ or Mg2+, hanging drop vapour diffusion method, 30 mg/ml protein in solution with 17 mM UDP-Gal, and 17 mM MgCl2 or MnCl2, precipitated by 10% v/v dioxane, 100 mM MES-NaOH, pH 6.5, and 2.0M ammonium sulfate, room temperature, X-ray diffraction structure determination and analysis at 2.3 A resolution, determination of conformation stereochemistry, modeling

Bos taurus

Protein Variants

Protein Variants	Comment	Organism
M344A	site-directed mutagenesis, altered metal ion specificity compared to the wild-type enzyme	Bos taurus
M344E	site-directed mutagenesis, altered metal ion specificity compared to the wild-type enzyme	Bos taurus
M344H	site-directed mutagenesis, the mutant shows altered conformational changes upon binding of Mn2+ and substrates or substrate analogues compared to the wild-type enzyme, it forms the closed conformation with bound Mn2+ and UDP-hexanolamine, loss of 98% of Mn2+ binding activity, increased activity with Mg2+	Bos taurus
M344Q	site-directed mutagenesis, altered metal ion specificity compared to the wild-type enzyme	Bos taurus
M344S	site-directed mutagenesis, altered metal ion specificity compared to the wild-type enzyme	Bos taurus

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
additional information	-	additional information	kinetics, wild-type and mutant M344H enzymes	Bos taurus

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining
Golgi apparatus	-	Bos taurus	5794	-
membrane	type II membrane-bound protein	Bos taurus	16020	-

Metals/Ions

Metals/Ions	Comment	Organism
Ca2+	active only with mutant enzymes M334H and M344E, no activity with wild-type enzyme and mutants M344A, M344S, and M344Q	Bos taurus
Co2+	less active than Mn2+ with wild-type and mutant enzymes	Bos taurus
Mg2+	active only with mutant enzymes M334H and M344E, no activity with wild-type enzyme and mutants M344A, M344S, and M344Q	Bos taurus
Mn2+	required, metal binding site structure with an uncommon coordination to the Sdelta atom of Met344, the site is located in the hinge region of along flexible loop, which changes from open to closed conformation upon binding of Mn2+ and UDP-galactose creating an oligosaccharide binding site in the enzyme structure, effect occurs specifically with UDP-galactose, not with other UDP-sugars,overview	Bos taurus
additional information	metal ion specificity of wild-type and mutant enzymes, overview	Bos taurus
Sr2+	active only with mutant enzymes M334H and M344E, no activity with wild-type enzyme and mutants M344A, M344S, and M344Q	Bos taurus
Zn2+	less active than Mn2+ with wild-type and mutant enzymes	Bos taurus

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
UDP-galactose + N-acetyl-D-glucosamine	Bos taurus	-	UDP + N-acetyllactosamine	-	?

Organism

Organism	UniProt	Comment	Textmining
Bos taurus	-	-	-

Reaction

Reaction	Comment	Organism	Reaction ID
UDP-alpha-D-galactose + N-acetyl-D-glucosamine = UDP + N-acetyllactosamine	the GlcNAc residue at the nonreducing end of chitobiose makes extensive hydrophobic interactions with the highly conserved Tyr286	Bos taurus	a

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
additional information	-	metal ion specificity of wild-type and mutant enzymes, overview	Bos taurus
0.00000013	-	mutant M344H in presence of 5 mM Mn2+	Bos taurus
0.00000032	-	mutant M344E in presence of 5 mM Mn2+	Bos taurus
0.00000191	-	mutant M344Q in presence of 5 mM Mn2+	Bos taurus
0.00000197	-	mutant M344S in presence of 5 mM Mn2+	Bos taurus
0.00000416	-	mutant M344A in presence of 5 mM Mn2+	Bos taurus
0.00000535	-	wild-type enzyme in presence of 5 mM Mn2+	Bos taurus

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
UDP-galactose + N-acetyl-D-glucosamine	-	Bos taurus	UDP + N-acetyllactosamine	-	?
UDP-galactose + N-acetyl-D-glucosamine	specific for UDP-galactose	Bos taurus	UDP + N-acetyllactosamine	-	?

Synonyms

Synonyms	Comment	Organism
beta1,4-galactosyltransferase-I	-	Bos taurus
beta4Gal-T1	-	Bos taurus

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
30	-	assay at	Bos taurus

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
0.097	-	UDP-galactose	mutant M344H, pH 8.0, 30°C	Bos taurus
3.6	-	UDP-galactose	wild-type enzyme, pH 8.0, 30°C	Bos taurus

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
8	-	assay at	Bos taurus