'''T152C MUTANT GLYCOSYLASPARAGINASE FROM FLAVOBACTERIUM MENINGOSEPTICUM'''
===T152C MUTANT GLYCOSYLASPARAGINASE FROM FLAVOBACTERIUM MENINGOSEPTICUM===
==Overview==
<!--
Glycosylasparaginase (GA) is a member of a novel family of N-terminal nucleophile hydrolases that catalytically use an N-terminal residue as both a polarizing base and a nucleophile. These enzymes are activated from a single chain precursor by intramolecular autoproteolysis to yield the N-terminal nucleophile. A deficiency of GA results in the human genetic disorder known as aspartylglycosaminuria. In this study, we report the crystal structure of recombinant GA from Flavobacterium meningosepticum. Similar to the human structure, the bacterial GA forms an alphabetabetaalpha sandwich. However, some significant differences are observed between the Flavobacterium and human structures. The active site of Flavobacterium glycosylasparaginase is in an open conformation when compared with the human structure. We also describe the structure of a mutant wherein the N-terminal nucleophile Thr152 is substituted by a cysteine. In the bacterial GA crystals, we observe a heterotetrameric structure similar to that found in the human structure, as well as that observed in solution for eukaryotic glycosylasparaginases. The results confirm the suitability of the bacterial enzyme as a model to study the consequences of mutations in aspartylglycosaminuria patients. They also suggest that further studies are necessary to understand the detail mechanism of this enzyme. The presence of the heterotetrameric structure in the crystals is significant because dimerization of precursors has been suggested in the human enzyme to be a prerequisite to trigger autoproteolysis.
The line below this paragraph, {{ABSTRACT_PUBMED_9685368}}, adds the Publication Abstract to the page
(as it appears on PubMed at http://www.pubmed.gov), where 9685368 is the PubMed ID number.
-->
{{ABSTRACT_PUBMED_9685368}}
==About this Structure==
==About this Structure==
Line 28:
Line 32:
[[Category: Mutant]]
[[Category: Mutant]]
[[Category: N-terminal nucleophile hydrolase]]
[[Category: N-terminal nucleophile hydrolase]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 04:53:00 2008''
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Jul 27 21:07:18 2008''
Revision as of 21:07, 27 July 2008
This article has been automatically seeded. Changes to this page should pertain to the PDB entry only and not to the protein or biomolecule in general.
