1m9h
From Proteopedia
(New page: 200px<br /><applet load="1m9h" size="450" color="white" frame="true" align="right" spinBox="true" caption="1m9h, resolution 2.0Å" /> '''Corynebacterium 2,5-D...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1m9h.jpg|left|200px]]<br /><applet load="1m9h" size=" | + | [[Image:1m9h.jpg|left|200px]]<br /><applet load="1m9h" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1m9h, resolution 2.0Å" /> | caption="1m9h, resolution 2.0Å" /> | ||
'''Corynebacterium 2,5-DKGR A and Phe 22 replaced with Tyr (F22Y), Lys 232 replaced with Gly (K232G), Arg 238 replaced with His (R238H)and Ala 272 replaced with Gly (A272G)in presence of NADH cofactor'''<br /> | '''Corynebacterium 2,5-DKGR A and Phe 22 replaced with Tyr (F22Y), Lys 232 replaced with Gly (K232G), Arg 238 replaced with His (R238H)and Ala 272 replaced with Gly (A272G)in presence of NADH cofactor'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Corynebacterium 2,5-Diketo-D-gluconic acid reductase (2,5-DKGR) catalyzes | + | Corynebacterium 2,5-Diketo-D-gluconic acid reductase (2,5-DKGR) catalyzes the reduction of 2,5-diketo-D-gluconic acid (2,5-DKG) to 2-Keto-L-gulonic acid (2-KLG). 2-KLG is an immediate precursor to L-ascorbic acid (vitamin C), and 2,5-DKGR is, therefore, an important enzyme in a novel industrial method for the production of vitamin C. 2,5-DKGR, as with most other members of the aldo-keto reductase (AKR) superfamily, exhibits a preference for NADPH compared to NADH as a cofactor in the stereo-specific reduction of substrate. The application of 2,5-DKGR in the industrial production of vitamin C would be greatly enhanced if NADH could be efficiently utilized as a cofactor. A mutant form of 2,5-DKGR has previously been identified that exhibits two orders of magnitude higher activity with NADH in comparison to the wild-type enzyme, while retaining a high level of activity with NADPH. We report here an X-ray crystal structure of the holo form of this mutant in complex with NADH cofactor, as well as thermodynamic stability data. By comparing the results to our previously reported X-ray structure of the holo form of wild-type 2,5-DKGR in complex with NADPH, the structural basis of the differential NAD(P)H selectivity of wild-type and mutant 2,5-DKGR enzymes has been identified. |
==About this Structure== | ==About this Structure== | ||
| - | 1M9H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Corynebacterium_sp. Corynebacterium sp.] with SO4 and NAD as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1M9H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Corynebacterium_sp. Corynebacterium sp.] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=NAD:'>NAD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M9H OCA]. |
==Reference== | ==Reference== | ||
| Line 19: | Line 19: | ||
[[Category: tim-barrel]] | [[Category: tim-barrel]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:52:59 2008'' |
Revision as of 11:53, 21 February 2008
|
Corynebacterium 2,5-DKGR A and Phe 22 replaced with Tyr (F22Y), Lys 232 replaced with Gly (K232G), Arg 238 replaced with His (R238H)and Ala 272 replaced with Gly (A272G)in presence of NADH cofactor
Overview
Corynebacterium 2,5-Diketo-D-gluconic acid reductase (2,5-DKGR) catalyzes the reduction of 2,5-diketo-D-gluconic acid (2,5-DKG) to 2-Keto-L-gulonic acid (2-KLG). 2-KLG is an immediate precursor to L-ascorbic acid (vitamin C), and 2,5-DKGR is, therefore, an important enzyme in a novel industrial method for the production of vitamin C. 2,5-DKGR, as with most other members of the aldo-keto reductase (AKR) superfamily, exhibits a preference for NADPH compared to NADH as a cofactor in the stereo-specific reduction of substrate. The application of 2,5-DKGR in the industrial production of vitamin C would be greatly enhanced if NADH could be efficiently utilized as a cofactor. A mutant form of 2,5-DKGR has previously been identified that exhibits two orders of magnitude higher activity with NADH in comparison to the wild-type enzyme, while retaining a high level of activity with NADPH. We report here an X-ray crystal structure of the holo form of this mutant in complex with NADH cofactor, as well as thermodynamic stability data. By comparing the results to our previously reported X-ray structure of the holo form of wild-type 2,5-DKGR in complex with NADPH, the structural basis of the differential NAD(P)H selectivity of wild-type and mutant 2,5-DKGR enzymes has been identified.
About this Structure
1M9H is a Single protein structure of sequence from Corynebacterium sp. with and as ligands. Full crystallographic information is available from OCA.
Reference
Structural alteration of cofactor specificity in Corynebacterium 2,5-diketo-D-gluconic acid reductase., Sanli G, Banta S, Anderson S, Blaber M, Protein Sci. 2004 Feb;13(2):504-12. Epub 2004 Jan 10. PMID:14718658
Page seeded by OCA on Thu Feb 21 13:52:59 2008
Categories: Corynebacterium sp. | Single protein | Blaber, M. | Sanli, G. | NAD | SO4 | Tim-barrel
