Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary extracted from

  • Yoshikane, Y.; Yokochi, N.; Yamasaki, M.; Mizutani, K.; Ohnishi, K.; Mikami, B.; Hayashi, H.; Yagi, T.
    Crystal structure of pyridoxamine-pyruvate aminotransferase from Mesorhizobium loti MAFF303099 (2008), J. Biol. Chem., 283, 1120-1127.
    View publication on PubMed

Cloned(Commentary)

EC Number Cloned (Comment) Organism
2.6.1.30 expression in Escherichia coli Mesorhizobium loti

Crystallization (Commentary)

EC Number Crystallization (Comment) Organism
2.6.1.30 native enzyme, space group P43212, diffraction to 2.0 A resolution. Complexes with pyridoxamine, pyridoxal, and pyridoxyl-L-alanine at 1.7 A, 1.7 A, and 2.0 A resolution, respectively. Enzyme is a homotetramer and each subunit is composed of a large N-terminal domain, consisting of seven beta-sheets and eight alpha-helices, and a smaller C-terminal domain, consisting of three beta-sheets and four alpha-helices. The substrate pyridoxal is bound through an aldimine linkage to Lys197 in the active site. The carboxylate group of the substrate amino/keto acid is hydrogen-bonded to Arg336 and Arg345 Mesorhizobium loti

Protein Variants

EC Number Protein Variants Comment Organism
2.6.1.30 E68A low pyridoxamine 5'-phosphate:pyruvate aminotransferase activity, decrease in activity towards pyridoxamine Mesorhizobium loti
2.6.1.30 E68G low pyridoxamine 5'-phosphate:pyruvate aminotransferase activity, decrease in activity towards pyridoxamine Mesorhizobium loti
2.6.1.30 R336A significant decrease in affinity for pyruvate Mesorhizobium loti

KM Value [mM]

EC Number KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
2.6.1.30 0.044
-
 pyridoxamine wild-type, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 0.1
-
 pyridoxamine mutant R336A, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 0.34
-
 pyruvate wild-type, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 1.3
-
 pyridoxamine mutant E68A, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 2.5
-
 pyridoxamine mutant E68G, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 3.4
-
 pyridoxamine 5'-phosphate mutant E68A, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 6.9
-
 pyruvate mutant R336A, pH 9.0, 30°C Mesorhizobium loti

Organism

EC Number Organism UniProt Comment Textmining
2.6.1.30 Mesorhizobium loti Q988B8
-
-
2.6.1.30 Mesorhizobium loti MAFF303099 Q988B8
-
-

Reaction

EC Number Reaction Comment Organism Reaction ID
2.6.1.30 pyridoxamine + pyruvate = pyridoxal + L-alanine enzyme first binds pyridoxamine and then forms a Michaelis complex with the incoming pyruvate. The ketimine is formed through nucleophilic attack of the N-4' atom of pyridoxamine on the alpha-carbon atom of pyruvate, which is followed by the release of a water molecule. The stereospecific 1,3-prototropic shift between the ketimine and external aldimine via the quinonoid intermediate is accomplished through general base catalysis by Lys197. Pyridoxal and L-alanine are formed from the external aldimine and released from enzyme Mesorhizobium loti
a

Substrates and Products (Substrate)

EC Number Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
2.6.1.30 pyridoxamine + pyruvate
-
 Mesorhizobium loti pyridoxal + L-alanine
-
 ?
2.6.1.30 pyridoxamine + pyruvate
-
 Mesorhizobium loti MAFF303099 pyridoxal + L-alanine
-
 ?
2.6.1.30 pyridoxamine 5'-phosphate + pyruvate
-
 Mesorhizobium loti pyridoxal 5'-phosphate + L-alanine
-
 ?
2.6.1.30 pyridoxamine 5'-phosphate + pyruvate
-
 Mesorhizobium loti MAFF303099 pyridoxal 5'-phosphate + L-alanine
-
 ?

Turnover Number [1/s]

EC Number Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
2.6.1.30 0.062
-
 pyridoxamine 5'-phosphate mutant E68G, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 0.22
-
 pyridoxamine 5'-phosphate mutant E68A, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 0.77
-
 pyridoxamine mutant E68G, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 0.78
-
 pyridoxamine mutant E68A, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 2 8 pyridoxamine mutant R336A, pH 9.0, 30°C Mesorhizobium loti
2.6.1.30 2 8 pyridoxamine wild-type, pH 9.0, 30°C Mesorhizobium loti

Cofactor

EC Number Cofactor Comment Organism Structure
2.6.1.30 pyridoxal 5'-phosphate the bulky side chain of Glu68 interferes with the binding of the phosphate moiety of pyridoxal 5'-phosphate and makes the enzyme specific to pyridoxal Mesorhizobium loti