Cofactors

There are no Cofactors for this Enzyme

Reaction Mechanism

alpha,alpha-trehalose-phosphate synthase (UDP-forming) By Reference

Escherichia coli trehalose-6-phosphate synthase is part of the glycosyl transferase family 20, the retaining glycosyl transferases. It is able to catalyse the condensation between Glucose-6-phosphate and UDP-glucose to form trehalose-6-phosphate, an important metabolite for many bacteria and plants. Interest in the enzyme stems both from the study of the unusual reaction mechanism and the fact that it plays a key role in bacterial cell wall synthesis in M. tuberculosis, so is a possible target for antibiotics. It displays sequence and structural identity with the glycogen phosphorylases in particular, suggesting a common mechanism and evolutionary origin. Also found to be similar is the pseudo-glycosyltransferase VldE involved in validoxylamine A 7'-phosphate synthesis.




• Summary
• Step 1
• Step 2
• Products

The reaction mechanism proceeds via an SNi type, meaning internal return whereby nucleophilic attack occurs on the same side as the leaving group departs. The ring oxygen of the UDP glucose donates electron density to C1 to allow the UDP to leave the molecule. This forms a shortly lived oxocarbenium ion stabilised by His 154 and Asp 361. Nucleophilic attack from the glucose-6-phosphate OH group on the anomeric carbon of glucose ensures that the configuration is retained to give the disaccharide product. UDP phosphate forming a hydrogen bond to the OH 1 on the acceptor molecule stabilises the negative charges developing on pyrophosphate, promoting UDP as a leaving group and also positions glucose-6-phosphate for nucleophilic attack. The activation of the OH towards nucleophilic attack is accomplished by the UDP moiety acting as a general base to remove a proton.

Catalytic Residues

AA	Uniprot	Uniprot Resid	PDB	PDB Resid
His	P31677	155	1uqt	155
Asp	P31677	362	1uqt	362

Step Components

overall reactant used, proton transfer, overall product formed, intermediate formation, bimolecular nucleophilic substitution, heterolysis, elimination (not covered by the Ingold mechanisms)



Step 1.

Cleavage of glycosidic bond between C1 and O while hydrogen bonds form between the OH on acceptor and O of phosphate.



Step 2.

Oxocarbenium ion intermediate generated is very short-lived. Concomitant Proton transfer and nucleophilic attack of O1 on glucose-6-phosphate on anomeric carbon on glucose intermediate.



Products.

The products of the reaction.

View Reaction Mechanisms in M-CSA

Reaction Parameters

There are no kinetic parameters information for this Enzyme

Associated Proteins

Citations

• Transcriptomic and metabolomic analyses reveal that ABA increases the salt tolerance of rice significantly correlated with jasmonic acid biosynthesis and flavonoid biosynthesis.
• Transcriptome and Metabolome Reveal Distinct Sugar Accumulation Pattern between PCNA and PCA Mature Persimmon Fruit.
• Comparative gut proteomics study revealing adaptive physiology of Eurasian spruce bark beetle, Ips typographus (Coleoptera: Scolytinae)
• Salinity stress endurance of the plants with the aid of bacterial genes.
• Metabolic framework of spontaneous and synthetic sourdough metacommunities to reveal microbial players responsible for resilience and performance.
• Integrating Transcriptional, Metabolic, and Physiological Responses to Drought Stress in Ilex paraguariensis Roots.
• In vitro and in silico assessment of probiotic and functional properties of Bacillus subtilis DE111^®.
• Glycine-Induced Phosphorylation Plays a Pivotal Role in Energy Metabolism in Roots and Amino Acid Metabolism in Leaves of Tea Plant.
• Integrative Transcriptome and Metabolome Profiles Reveal Common and Unique Pathways Involved in Seed Initial Imbibition Under Artificial and Natural Salt Stresses During Germination of Halophyte Quinoa.
• Draft Genome Sequence of the Anoxygenic Phototrophic Bacterium Rhodomicrobium sp. Strain Az07, Isolated from a Brackish Canal.
• Wheat Grains as a Sustainable Source of Protein for Health.