2yqh
From Proteopedia
| Line 4: | Line 4: | ||
==Overview== | ==Overview== | ||
| - | Uridine-diphospho-N-acetylglucosamine (UDP-GlcNAc) is a precursor of the | + | Uridine-diphospho-N-acetylglucosamine (UDP-GlcNAc) is a precursor of the bacterial and fungal cell wall. It is also used in a component of N-linked glycosylation and the glycosylphosphoinositol anchor of eukaryotic proteins. It is synthesized from N-acetylglucosamine-1-phosphate (GlcNAc-1-P) and uridine-5'-triphosphate (UTP) by UDP-GlcNAc pyrophosphorylase (UAP). This is an S(N)2 reaction; the non-esterified oxygen atom of the GlcNAc-1-P phosphate group attacks the alpha-phosphate group of UTP. We determined crystal structures of UAP from Candida albicans (CaUAP1) without any ligands and also complexed with its substrate or with its product. The series of structures in different forms shows the induced fit movements of CaUAP1. Three loops approaching the ligand molecule close the active site when ligand is bound. In addition, Lys-421, instead of the metal ion in prokaryotic UAPs, is coordinated by both phosphate groups of UDP-Glc-NAc and acts as a cofactor. However, a magnesium ion enhances the enzymatic activity of CaUAP1, and thus we propose that the magnesium ion increases the affinity between UTP and the enzyme by coordinating to the alpha- and gamma-phosphate group of UTP. |
==About this Structure== | ==About this Structure== | ||
| Line 10: | Line 10: | ||
==Reference== | ==Reference== | ||
| - | Crystal structure of uridine-diphospho-N-acetylglucosamine pyrophosphorylase from Candida albicans and catalytic reaction mechanism., Maruyama D, Nishitani Y, Nonaka T, Kita A, Fukami TA, Mio T, Yamada-Okabe H, Yamada-Okabe T, Miki K, J Biol Chem. 2007 Mar 28 | + | Crystal structure of uridine-diphospho-N-acetylglucosamine pyrophosphorylase from Candida albicans and catalytic reaction mechanism., Maruyama D, Nishitani Y, Nonaka T, Kita A, Fukami TA, Mio T, Yamada-Okabe H, Yamada-Okabe T, Miki K, J Biol Chem. 2007 Jun 8;282(23):17221-30. Epub 2007 Mar 28. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17392279 17392279] |
[[Category: Candida albicans]] | [[Category: Candida albicans]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| Line 30: | Line 30: | ||
[[Category: uridine-diphospho-n-acetylglucosamine]] | [[Category: uridine-diphospho-n-acetylglucosamine]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:57:05 2008'' |
Revision as of 16:57, 21 February 2008
|
Crystal structure of uridine-diphospho-N-acetylglucosamine pyrophosphorylase from Candida albicans, in the substrate-binding form
Overview
Uridine-diphospho-N-acetylglucosamine (UDP-GlcNAc) is a precursor of the bacterial and fungal cell wall. It is also used in a component of N-linked glycosylation and the glycosylphosphoinositol anchor of eukaryotic proteins. It is synthesized from N-acetylglucosamine-1-phosphate (GlcNAc-1-P) and uridine-5'-triphosphate (UTP) by UDP-GlcNAc pyrophosphorylase (UAP). This is an S(N)2 reaction; the non-esterified oxygen atom of the GlcNAc-1-P phosphate group attacks the alpha-phosphate group of UTP. We determined crystal structures of UAP from Candida albicans (CaUAP1) without any ligands and also complexed with its substrate or with its product. The series of structures in different forms shows the induced fit movements of CaUAP1. Three loops approaching the ligand molecule close the active site when ligand is bound. In addition, Lys-421, instead of the metal ion in prokaryotic UAPs, is coordinated by both phosphate groups of UDP-Glc-NAc and acts as a cofactor. However, a magnesium ion enhances the enzymatic activity of CaUAP1, and thus we propose that the magnesium ion increases the affinity between UTP and the enzyme by coordinating to the alpha- and gamma-phosphate group of UTP.
About this Structure
2YQH is a Single protein structure of sequence from Candida albicans with , , and as ligands. Active as UDP-N-acetylglucosamine diphosphorylase, with EC number 2.7.7.23 Full crystallographic information is available from OCA.
Reference
Crystal structure of uridine-diphospho-N-acetylglucosamine pyrophosphorylase from Candida albicans and catalytic reaction mechanism., Maruyama D, Nishitani Y, Nonaka T, Kita A, Fukami TA, Mio T, Yamada-Okabe H, Yamada-Okabe T, Miki K, J Biol Chem. 2007 Jun 8;282(23):17221-30. Epub 2007 Mar 28. PMID:17392279
Page seeded by OCA on Thu Feb 21 18:57:05 2008
Categories: Candida albicans | Single protein | UDP-N-acetylglucosamine diphosphorylase | Kita, A. | Maruyama, D. | Miki, K. | Nishitani, Y. | Nonaka, T. | GN1 | GOL | MG | SO4 | Crystal structure | N-acetylglucosamine | N-acetylglucosamine-1-phosphate | Pyrophosphorylase | Uridine-diphospho-n-acetylglucosamine
