On the biosynthesis of free and covalently bound PQQ Glutamic acid decarboxylase from Escherichia coli is a pyridoxo‐quinoprotein

FEBS Letters

Groen, Barend W.¹  Duine, Johannis A.¹  van der Meer, Robert A.¹ 

[1] Department of Microbiology and Enzymology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands

关键词: Pyrroloquinoline quinone;    Cofactor;    Quinoprotein;    Glutamic acid decarboxylase;    Glucose dehydrogenase;    Pyridoxal phosphate;    (E. coli);   

DOI  :  10.1016/0014-5793(89)80263-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Analysis of glutamic acid decarboxylase (GDC) (EC 4.1.1.15) from Escherichia coli ATCC 11246 revealed the presence of six pyridoxal phosphates (PLPs) as well as six covalently bound pyrroloquinoline quinones (PQQs) per hexameric enzyme molecule. This is the second example of a pyridoxo-quinoprotein, suggesting that other atypical pyridoxoproteins (PLP-containing enzymes) have similar cofactor composition. Since the organism did not produce free PQQ and its quinoprotein glucose dehydrogenase was present in the apo form, free PQQ is not used in the assemblage of GDC. Most probably, biosynthesis of covalently bound cofactor occurs in situ via a route which is different from that of free PQQ. Thus, organisms previously believed to be unable to synthesize (free) PQQ could in fact be able to produce quinoproteins with covalently bound cofactor. Implications for the role of PQQ in eukaryotic cells are discussed.

【 授权许可】

Unknown