Reaction participants Show >> << Hide
- Name help_outline UDP-α-D-glucose Identifier CHEBI:58885 (Beilstein: 3827329) help_outline Charge -2 Formula C15H22N2O17P2 InChIKeyhelp_outline HSCJRCZFDFQWRP-JZMIEXBBSA-L SMILEShelp_outline OC[C@H]1O[C@H](OP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](O)[C@@H]2O)n2ccc(=O)[nH]c2=O)[C@H](O)[C@@H](O)[C@@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 223 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,048 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline UDP-4-dehydro-6-deoxy-α-D-glucose Identifier CHEBI:85329 Charge -2 Formula C15H20N2O16P2 InChIKeyhelp_outline DDWGQQADOIMFOI-JPHISPRKSA-L SMILEShelp_outline C[C@H]1O[C@H](OP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](O)[C@@H]2O)n2ccc(=O)[nH]c2=O)[C@H](O)[C@@H](O)C1=O 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:21500 | RHEA:21501 | RHEA:21502 | RHEA:21503 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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The formation of UDP-L-rhamnose from UDP-D-glucose by an enzyme preparation of red campion (Silene dioica (L) Clairv) leaves.
Kamsteeg J., Van Brederode J., Van Nigtevecht G.
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Functional analysis of Arabidopsis thaliana RHM2/MUM4, a multidomain protein involved in UDP-D-glucose to UDP-L-rhamnose conversion.
Oka T., Nemoto T., Jigami Y.
UDP-L-rhamnose is required for the biosynthesis of cell wall rhamnogalacturonan-I, rhamnogalacturonan-II, and natural compounds in plants. It has been suggested that the RHM2/MUM4 gene is involved in conversion of UDP-D-glucose to UDP-L-rhamnose on the basis of its effect on rhamnogalacturonan-I-d ... >> More
UDP-L-rhamnose is required for the biosynthesis of cell wall rhamnogalacturonan-I, rhamnogalacturonan-II, and natural compounds in plants. It has been suggested that the RHM2/MUM4 gene is involved in conversion of UDP-D-glucose to UDP-L-rhamnose on the basis of its effect on rhamnogalacturonan-I-directed development in Arabidopsis thaliana. RHM2/MUM4-related genes, RHM1 and RHM3, can be found in the A. thaliana genome. Here we present direct evidence that all three RHM proteins have UDP-D-glucose 4,6-dehydratase, UDP-4-keto-6-deoxy-D-glucose 3,5-epimerase, and UDP-4-keto-L-rhamnose 4-keto-reductase activities in the cytoplasm when expressed in the yeast Saccharomyces cerevisiae. Functional domain analysis revealed that the N-terminal region of RHM2 (RHM2-N; amino acids 1-370) has the first activity and the C-terminal region of RHM2 (RHM2-C; amino acids 371-667) has the two following activities. This suggests that RHM2 converts UDP-d-glucose to UDP-L-rhamnose via an UDP-4-keto-6-deoxy-D-glucose intermediate. Site-directed mutagenesis of RHM2 revealed that mucilage defects in MUM4-1 and MUM4-2 mutant seeds of A. thaliana are caused by abolishment of RHM2 enzymatic activity in the mutant strains and furthermore, that the GXXGXX(G/A) and YXXXK motifs are important for enzymatic activity. Moreover, a kinetic analysis of purified His(6)-tagged RHM2-N protein revealed 5.9-fold higher affinity of RHM2 for UDP-D-glucose than for dTDP-D-glucose, the preferred substrate for dTDP-D-glucose 4,6-dehydratase from bacteria. RHM2-N activity is strongly inhibited by UDP-L-rhamnose, UDP-D-xylose, and UDP but not by other sugar nucleotides, suggesting that RHM2 maintains cytoplasmic levels of UDP-D-glucose and UDP-L-rhamnose via feedback inhibition by UDP-L-rhamnose and UDP-D-xylose. << Less
J. Biol. Chem. 282:5389-5403(2007) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.