1nxc
From Proteopedia
(New page: 200px<br /><applet load="1nxc" size="450" color="white" frame="true" align="right" spinBox="true" caption="1nxc, resolution 1.51Å" /> '''Structure of mouse G...) |
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| - | [[Image:1nxc.jpg|left|200px]]<br /><applet load="1nxc" size=" | + | [[Image:1nxc.jpg|left|200px]]<br /><applet load="1nxc" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1nxc, resolution 1.51Å" /> | caption="1nxc, resolution 1.51Å" /> | ||
'''Structure of mouse Golgi alpha-1,2-mannosidase IA reveals the molecular basis for substrate specificity among Class I enzymes (family 47 glycosidases)'''<br /> | '''Structure of mouse Golgi alpha-1,2-mannosidase IA reveals the molecular basis for substrate specificity among Class I enzymes (family 47 glycosidases)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Three subfamilies of mammalian Class 1 processing alpha1,2-mannosidases | + | Three subfamilies of mammalian Class 1 processing alpha1,2-mannosidases (family 47 glycosidases) play critical roles in the maturation of Asn-linked glycoproteins in the endoplasmic reticulum (ER) and Golgi complex as well as influencing the timing and recognition for disposal of terminally unfolded proteins by ER-associated degradation. In an effort to define the structural basis for substrate recognition among Class 1 mannosidases, we have crystallized murine Golgi mannosidase IA (space group P2(1)2(1)2(1)), and the structure was solved to 1.5-A resolution by molecular replacement. The enzyme assumes an (alphaalpha)(7) barrel structure with a Ca(2+) ion coordinated at the base of the barrel similar to other Class 1 mannosidases. Critical residues within the barrel structure that coordinate the Ca(2+) ion or presumably bind and catalyze the hydrolysis of the glycone are also highly conserved. A Man(6)GlcNAc(2) oligosaccharide attached to Asn(515) in the murine enzyme was found to extend into the active site of an adjoining protein unit in the crystal lattice in a presumed enzyme-product complex. In contrast to an analogous complex previously isolated for Saccharomyces cerevisiae ER mannosidase I, the oligosaccharide in the active site of the murine Golgi enzyme assumes a different conformation to present an alternate oligosaccharide branch into the active site pocket. A comparison of the observed protein-carbohydrate interactions for the murine Golgi enzyme with the binding cleft topologies of the other family 47 glycosidases provides a framework for understanding the structural basis for substrate recognition among this class of enzymes. |
==About this Structure== | ==About this Structure== | ||
| - | 1NXC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with MAN and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Mannosyl-oligosaccharide_1,2-alpha-mannosidase Mannosyl-oligosaccharide 1,2-alpha-mannosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.113 3.2.1.113] Full crystallographic information is available from [http:// | + | 1NXC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with <scene name='pdbligand=MAN:'>MAN</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Mannosyl-oligosaccharide_1,2-alpha-mannosidase Mannosyl-oligosaccharide 1,2-alpha-mannosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.113 3.2.1.113] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NXC OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Karaveg, K.]] | [[Category: Karaveg, K.]] | ||
| - | [[Category: Liu, Z | + | [[Category: Liu, Z J.]] |
| - | [[Category: Moremen, K | + | [[Category: Moremen, K W.]] |
[[Category: Rose, J.]] | [[Category: Rose, J.]] | ||
| - | [[Category: SECSG, Southeast | + | [[Category: SECSG, Southeast Collaboratory for Structural Genomics.]] |
[[Category: Tempel, W.]] | [[Category: Tempel, W.]] | ||
| - | [[Category: Wang, B | + | [[Category: Wang, B C.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: MAN]] | [[Category: MAN]] | ||
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[[Category: structural genomics]] | [[Category: structural genomics]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:11:04 2008'' |
Revision as of 12:11, 21 February 2008
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Structure of mouse Golgi alpha-1,2-mannosidase IA reveals the molecular basis for substrate specificity among Class I enzymes (family 47 glycosidases)
Overview
Three subfamilies of mammalian Class 1 processing alpha1,2-mannosidases (family 47 glycosidases) play critical roles in the maturation of Asn-linked glycoproteins in the endoplasmic reticulum (ER) and Golgi complex as well as influencing the timing and recognition for disposal of terminally unfolded proteins by ER-associated degradation. In an effort to define the structural basis for substrate recognition among Class 1 mannosidases, we have crystallized murine Golgi mannosidase IA (space group P2(1)2(1)2(1)), and the structure was solved to 1.5-A resolution by molecular replacement. The enzyme assumes an (alphaalpha)(7) barrel structure with a Ca(2+) ion coordinated at the base of the barrel similar to other Class 1 mannosidases. Critical residues within the barrel structure that coordinate the Ca(2+) ion or presumably bind and catalyze the hydrolysis of the glycone are also highly conserved. A Man(6)GlcNAc(2) oligosaccharide attached to Asn(515) in the murine enzyme was found to extend into the active site of an adjoining protein unit in the crystal lattice in a presumed enzyme-product complex. In contrast to an analogous complex previously isolated for Saccharomyces cerevisiae ER mannosidase I, the oligosaccharide in the active site of the murine Golgi enzyme assumes a different conformation to present an alternate oligosaccharide branch into the active site pocket. A comparison of the observed protein-carbohydrate interactions for the murine Golgi enzyme with the binding cleft topologies of the other family 47 glycosidases provides a framework for understanding the structural basis for substrate recognition among this class of enzymes.
About this Structure
1NXC is a Single protein structure of sequence from Mus musculus with and as ligands. Active as Mannosyl-oligosaccharide 1,2-alpha-mannosidase, with EC number 3.2.1.113 Full crystallographic information is available from OCA.
Reference
Structure of mouse Golgi alpha-mannosidase IA reveals the molecular basis for substrate specificity among class 1 (family 47 glycosylhydrolase) alpha1,2-mannosidases., Tempel W, Karaveg K, Liu ZJ, Rose J, Wang BC, Moremen KW, J Biol Chem. 2004 Jul 9;279(28):29774-86. Epub 2004 Apr 21. PMID:15102839
Page seeded by OCA on Thu Feb 21 14:11:04 2008
Categories: Mannosyl-oligosaccharide 1,2-alpha-mannosidase | Mus musculus | Single protein | Karaveg, K. | Liu, Z J. | Moremen, K W. | Rose, J. | SECSG, Southeast Collaboratory for Structural Genomics. | Tempel, W. | Wang, B C. | CA | MAN | Glycosidase | Mannosidase | Protein structure initiative | Psi | Secsg | Southeast collaboratory for structural genomics | Structural genomics
