This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1o7a
From Proteopedia
| Line 1: | Line 1: | ||
| - | [[Image:1o7a.gif|left|200px]]<br /><applet load="1o7a" size=" | + | [[Image:1o7a.gif|left|200px]]<br /><applet load="1o7a" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1o7a, resolution 2.25Å" /> | caption="1o7a, resolution 2.25Å" /> | ||
'''HUMAN BETA-HEXOSAMINIDASE B'''<br /> | '''HUMAN BETA-HEXOSAMINIDASE B'''<br /> | ||
| Line 10: | Line 10: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1O7A is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with NAG, GDL and EDO as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Beta-N-acetylhexosaminidase Beta-N-acetylhexosaminidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.52 3.2.1.52] Known structural/functional Site: <scene name='pdbsite=ABC:N-Glycosylation Site 3'>ABC</scene>. Full crystallographic information is available from [http:// | + | 1O7A is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=NAG:'>NAG</scene>, <scene name='pdbligand=GDL:'>GDL</scene> and <scene name='pdbligand=EDO:'>EDO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Beta-N-acetylhexosaminidase Beta-N-acetylhexosaminidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.52 3.2.1.52] Known structural/functional Site: <scene name='pdbsite=ABC:N-Glycosylation+Site+3'>ABC</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1O7A OCA]. |
==Reference== | ==Reference== | ||
| Line 34: | Line 34: | ||
[[Category: sphingolipid degradation]] | [[Category: sphingolipid degradation]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:54:23 2008'' |
Revision as of 07:54, 3 February 2008
|
HUMAN BETA-HEXOSAMINIDASE B
Contents |
Overview
Human lysosomal beta-hexosaminidases are dimeric enzymes composed of alpha, and beta-chains, encoded by the genes HEXA and HEXB. They occur in three, isoforms, the homodimeric hexosaminidases B (betabeta) and S (alphaalpha), and the heterodimeric hexosaminidase A (alphabeta), where dimerization is, required for catalytic activity. Allelic variations in the HEXA and HEXB, genes cause the fatal inborn errors of metabolism Tay-Sachs disease and, Sandhoff disease, respectively. Here, we present the crystal structure of, a complex of human beta-hexosaminidase B with a transition state analogue, inhibitor at 2.3A resolution (pdb 1o7a). On the basis of this structure, and previous studies on related enzymes, a retaining double-displacement, mechanism for glycosyl hydrolysis by beta-hexosaminidase B is proposed. In, the dimer structure, which is derived from an analysis of crystal packing, most of the mutations causing late-onset Sandhoff disease reside near the, dimer interface and are proposed to interfere with correct dimer, formation. The structure reported here is a valid template also for the, dimeric structures of beta-hexosaminidase A and S.
Disease
Known diseases associated with this structure: Sandhoff disease, infantile, juvenile, and adult forms OMIM:[606873], Spinal muscular atrophy, juvenile OMIM:[606873]
About this Structure
1O7A is a Single protein structure of sequence from Homo sapiens with , and as ligands. Active as Beta-N-acetylhexosaminidase, with EC number 3.2.1.52 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
The X-ray crystal structure of human beta-hexosaminidase B provides new insights into Sandhoff disease., Maier T, Strater N, Schuette CG, Klingenstein R, Sandhoff K, Saenger W, J Mol Biol. 2003 May 2;328(3):669-81. PMID:12706724
Page seeded by OCA on Sun Feb 3 09:54:23 2008
Categories: Beta-N-acetylhexosaminidase | Homo sapiens | Single protein | Klingenstein, R. | Maier, T. | Saenger, W. | Sandhoff, K. | Schuette, C. | Strater, N. | EDO | GDL | NAG | Ba8-barrel | Glycosidase | Glycosyl hydrolase | Hexosaminidase | Lysosomal | Sandhoff disease | Sphingolipid degradation
