Two mammalian glucosamine‐6‐phosphate deaminases: a structural and genetic study

FEBS Letters

Arreola, Rodrigo²  Morante, Maria L²  Valderrama, Brenda¹  Horjales, Eduardo² 

[1] Departamento de Bioingenieria, Instituto de Biotecnologı́a, Universidad Nacional Autónoma de México, PO Box 510-3, Cuernavaca, Morelos 62250, Mexico;Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologı́a, Universidad Nacional Autónoma de México, PO Box 510-3, Cuernavaca, Morelos 62250, Mexico

关键词: K-type allosteric system;    EST;    Isoenzyme;    GNPI;    GlcN6P-deaminase;    Ammonia capture and detoxification;   

DOI  :  10.1016/S0014-5793(03)00896-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Glucosamine-6-phosphate deaminase (EC 3.5.99.6) is an allosteric enzyme that catalyzes the reversible conversion of D-glucosamine-6-phosphate into D-fructose-6-phosphate and ammonium. Here we describe the existence of two mammalian glucosamine-6-phosphate deaminase enzymes. We present the crystallographic structure of one of them, the long human glucosamine-6-phosphate deaminase, at 1.75 Å resolution. Crystals belong to the space group P2₁2₁2₁ and present a whole hexamer in the asymmetric unit. The active-site lid (residues 162–182) presented significant structural differences among monomers. Interestingly the region with the largest differences, when compared with the Escherichia coli homologue, was found to be close to the active site. These structural differences can be related to the kinetic and allosteric properties of both mammalian enzymes.

【 授权许可】

Unknown