Functional complementation between the PDX1 vitamin B6 biosynthetic gene of Cercospora nicotianae and pdxJ of Escherichia coli

FEBS Letters

Ehrenshaft, Marilyn¹  Wetzel, Denise K¹  Daub, Margaret E¹  Denslow, Sheri A¹ 

[1] Department of Botany, North Carolina State University, Raleigh, NC 27695-7612, USA

关键词: SNZ;    YaaD;    SOR1;    PYROA;    Pyridoxal-5′-phosphate;    Pyridoxamine;   

DOI  :  10.1016/S0014-5793(04)00329-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The pathway for de novo vitamin B₆ biosynthesis has been characterized in Escherichia coli, however plants, fungi, archaebacteria, and most bacteria utilize an alternative pathway. Two unique genes of the alternative pathway, PDX1 and PDX2, have been described. PDX2 encodes a glutaminase, however the enzymatic function of the product encoded by PDX1 is not known. We conducted reciprocal transformation experiments to determine if there was functional homology between the E. coli pdxA and pdxJ genes and PDX1 of Cercospora nicotianae. Although expression of pdxJ and pdxA in C. nicotianae pdx1 mutants, either separately or together, failed to complement the pyridoxine mutation in this fungus, expression of PDX1 restored pyridoxine prototrophy to the E. coli pdxJ mutant. Expression of PDX1 in the E. coli pdxA mutant restored very limited ability to grow on medium lacking pyridoxine. We conclude that the PDX1 gene of the alternative B₆ pathway encodes a protein responsible for synthesis of the pyridoxine ring.

【 授权许可】

Unknown