1rp8
From Proteopedia
| Line 1: | Line 1: | ||
| - | [[Image:1rp8.gif|left|200px]] | + | [[Image:1rp8.gif|left|200px]] |
| - | + | ||
| - | '''Crystal structure of barley alpha-amylase isozyme 1 (amy1) inactive mutant d180a in complex with maltoheptaose''' | + | {{Structure |
| + | |PDB= 1rp8 |SIZE=350|CAPTION= <scene name='initialview01'>1rp8</scene>, resolution 2.00Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=CA:CALCIUM ION'>CA</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Alpha-amylase Alpha-amylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.1 3.2.1.1] | ||
| + | |GENE= AMY1.1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4513 Hordeum vulgare]) | ||
| + | }} | ||
| + | |||
| + | '''Crystal structure of barley alpha-amylase isozyme 1 (amy1) inactive mutant d180a in complex with maltoheptaose''' | ||
| + | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1RP8 is a [ | + | 1RP8 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Hordeum_vulgare Hordeum vulgare]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RP8 OCA]. |
==Reference== | ==Reference== | ||
| - | Oligosaccharide binding to barley alpha-amylase 1., Robert X, Haser R, Mori H, Svensson B, Aghajari N, J Biol Chem. 2005 Sep 23;280(38):32968-78. Epub 2005 Jul 19. PMID:[http:// | + | Oligosaccharide binding to barley alpha-amylase 1., Robert X, Haser R, Mori H, Svensson B, Aghajari N, J Biol Chem. 2005 Sep 23;280(38):32968-78. Epub 2005 Jul 19. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16030022 16030022] |
[[Category: Alpha-amylase]] | [[Category: Alpha-amylase]] | ||
[[Category: Hordeum vulgare]] | [[Category: Hordeum vulgare]] | ||
| Line 28: | Line 37: | ||
[[Category: x-ray diffraction]] | [[Category: x-ray diffraction]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 13:54:26 2008'' |
Revision as of 11:54, 20 March 2008
| |||||||
| , resolution 2.00Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | AMY1.1 (Hordeum vulgare) | ||||||
| Activity: | Alpha-amylase, with EC number 3.2.1.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of barley alpha-amylase isozyme 1 (amy1) inactive mutant d180a in complex with maltoheptaose
Overview
Enzymatic subsite mapping earlier predicted 10 binding subsites in the active site substrate binding cleft of barley alpha-amylase isozymes. The three-dimensional structures of the oligosaccharide complexes with barley alpha-amylase isozyme 1 (AMY1) described here give for the first time a thorough insight into the substrate binding by describing residues defining 9 subsites, namely -7 through +2. These structures support that the pseudotetrasaccharide inhibitor acarbose is hydrolyzed by the active enzymes. Moreover, sugar binding was observed to the starch granule-binding site previously determined in barley alpha-amylase isozyme 2 (AMY2), and the sugar binding modes are compared between the two isozymes. The "sugar tongs" surface binding site discovered in the AMY1-thio-DP4 complex is confirmed in the present work. A site that putatively serves as an entrance for the substrate to the active site was proposed at the glycone part of the binding cleft, and the crystal structures of the catalytic nucleophile mutant (AMY1D180A) complexed with acarbose and maltoheptaose, respectively, suggest an additional role for the nucleophile in the stabilization of the Michaelis complex. Furthermore, probable roles are outlined for the surface binding sites. Our data support a model in which the two surface sites in AMY1 can interact with amylose chains in their naturally folded form. Because of the specificities of these two sites, they may locate/orient the enzyme in order to facilitate access to the active site for polysaccharide chains. Moreover, the sugar tongs surface site could also perform the unraveling of amylose chains, with the aid of Tyr-380 acting as "molecular tweezers."
About this Structure
1RP8 is a Single protein structure of sequence from Hordeum vulgare. Full crystallographic information is available from OCA.
Reference
Oligosaccharide binding to barley alpha-amylase 1., Robert X, Haser R, Mori H, Svensson B, Aghajari N, J Biol Chem. 2005 Sep 23;280(38):32968-78. Epub 2005 Jul 19. PMID:16030022
Page seeded by OCA on Thu Mar 20 13:54:26 2008
