4‐O‐Phosphoryl‐l‐threonine, a substrate of the pdxC(serC) gene product involved in vitamin B 6 biosynthesis

FEBS Letters

Müller, Rolf¹  Klein, Matthias¹  Leistner, Eckhard¹  Drewke, Christel¹  Arenz, Ansgar¹  Clade, Dorothee¹ 

[1] Institut für Pharmazeutische Biologie, Rheinische Freidrich-Wilhelms-Universität Bonn, Nußallee 6, D-53115 Bonn, Germany

关键词: Escherichia coli;    Vitamin B6;    Pyridoxal phosphate;    3-O-Phospho-l-serine:2-Oxoglutarate aminotransferase;    4-O-Phosphoryl-l-threonine:2-Oxoglutarate aminotransferase;   

DOI  :  10.1016/0014-5793(96)00652-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The Escherichia coli pdxC(serC) gene codes for a transaminase (EC 2.6.1.52). The gene is involved in both pyridoxine (vitamin B₆) and serine biosynthesis and was over-expressed as a MalE/PdxC(SerC) fusion protein. The fusion protein was purified by affinity chromatography on an amylose resin and hydrolyzed in the presence of protease factor Xa. Both the fusion protein and the PdxC(SerC) protein were characterized (K _M value, turnover number, optimum pH). Both enzymes used 4-O-phosphoryl-l-threonine rather than 4-hydroxy-l-threonine as a substrate indicating that the phosphorylated rather than the non-phosphorylated amino acid is involved in pyridoxine biosynthesis. Pyridoxal phosphate was shown to be the cofactor for both enzymes and therefore seems to be involved in its own biosynthesis.

【 授权许可】

Unknown