PMID: 8846222

Authors:

Oinonen C, Tikkanen R, Rouvinen J, Peltonen L

Title:

Three-dimensional structure of human lysosomal aspartylglucosaminidase.

Journal:

Nat Struct Biol. 1995 Dec;2(12):1102-8.

Abstract:

The high resolution crystal structure of human lysosomal aspartylglucosaminidase (AGA) has been determined. This lysosomal enzyme is synthesized as a single polypeptide precursor, which is immediately post-translationally cleaved into alpha- and beta-subunits. Two alpha- and beta-chains are found to pack together forming the final heterotetrameric structure. The catalytically essential residue, the N-terminal threonine of the beta-chain is situated in the deep pocket of the funnel-shaped active site. On the basis of the structure of the enzyme-product complex we present a catalytic mechanism for this lysosomal enzyme with an exceptionally high pH optimum. The three-dimensional structure also allows the prediction of the structural consequences of human mutations resulting in aspartylglucosaminuria (AGU), a lysosomal storage disease.