UDP‐galactose 4‐epimerase from Escherichia coli: existence of a catalytic monomer

FEBS Letters

Bhattacharyya, Debasish¹  Nayar, Suprabha¹ 

[1] Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Calcutta 70032, India

关键词: UDP-galactose 4-epimerase;    Subunit dissociation;    Catalytic monomer;    Size-exclusion HPLC;    Ultracentrifugation;    Epimerase;    UDP-galactose 4-epimerase (EC 5.1.3.2.);    UDP-gal;    UDP galactose;    UDP-glu;    UDP glucose;    SE-HPLC;    size-exclusion HPLC;    ANS;    1-anilino 8-naphthalene sulphonic acid;    PG;    phenyl glyoxal;    CD;    circular dichroism;   

DOI  :  10.1016/S0014-5793(97)00552-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

UDP-galactose 4-epimerase from Escherichia coli is a homodimer of molecular mass 39 kDa/subunit and requires NAD as a co-factor. X-ray crystallographic studies indicate two pyridine nucleotide co-factor-binding sites of the dimeric molecule situated in a symmetry-oriented manner. Size-exclusion HPLC of an equilibrium intermediate at 3 M urea suggests a monomeric holoenzyme structure that is catalytically active. Ultracentrifugal studies of the native enzyme in a 5–20% sucrose gradient at low protein concentration also indicate existence of a catalytic monomer. The monomer resembles the dimeric protein in stability and most of its physico–chemical properties.

【 授权许可】

Unknown