GO:0052751 GDP-mannose hydrolase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0052751 (GDP-mannose hydrolase activity) catalyzes the hydrolysis of GDP-mannose to GMP and mannose-1-phosphate, a reaction that cleaves the glycosidic bond at carbon rather than at phosphorus.
• The enzyme belongs to the Nudix hydrolase superfamily and shares homology with the MutT family, but uniquely acts as a glycosyl hydrolase rather than a pyrophosphatase.
• Its catalytic mechanism is dissociative and requires divalent metal ions, with kinetic and structural studies supporting a metal-assisted oxocarbenium-like transition state.
• GDP-mannose hydrolase activity influences GDP-mannose pools, which are critical for protein glycosylation, cell wall integrity, and microbial L-fucose production.
• In triple-negative breast cancer, GDP-mannose suppresses homologous recombination repair and potentiates antitumor immunity, linking this activity to DNA repair and immune surveillance.
• Defects in GMPPB, which affects GDP-mannose metabolism, cause a congenital disorder of glycosylation with lysosomal dysfunction and acid alpha-glucosidase deficiency.
Description
GDP-mannose hydrolase activity (GO:0052751) is a molecular function that catalyzes the hydrolysis of guanosine diphosphate mannose (GDP-mannose) into guanosine monophosphate (GMP) and mannose-1-phosphate. This reaction is unusual because it cleaves the bond between the sugar and the nucleotide at the anomeric carbon, rather than at the phosphate groups typical of Nudix hydrolases. The enzyme was first identified in Escherichia coli as a novel GDP-mannose mannosyl hydrolase sharing homology with the MutT family, and it has since been characterized structurally and kinetically. Researchers study GO:0052751 because it sits at the intersection of nucleotide sugar metabolism, protein glycosylation, and microbial physiology, with emerging links to cancer biology and congenital disorders of glycosylation.
GDP-mannose hydrolase activity At A Glance
| GO ID | GO:0052751 |
|---|---|
| GO term | GDP-mannose hydrolase activity |
| Ontology | molecular_function |
| Synonym | GDP-mannose pyrophosphatase activity |
| Major function | Catalyzes the hydrolysis of GDP-mannose to GMP and mannose-1-phosphate |
| Enzyme family | Nudix hydrolase superfamily, homologous to MutT family |
| Catalytic mechanism | Dissociative, metal-dependent glycosyl hydrolysis |
| Subcellular context | Cytosolic in bacteria and eukaryotes, influencing GDP-mannose pools |
What Is GO:0052751?
GO:0052751, GDP-mannose hydrolase activity, is defined as the catalysis of the reaction: GDP-mannose + H2O = GMP + mannose-1-phosphate. This activity is synonymous with GDP-mannose pyrophosphatase activity, although the reaction it catalyzes is a glycosyl hydrolysis rather than a pyrophosphate cleavage. The enzyme uses water to break the bond between the mannose moiety and the GDP portion, releasing GMP and mannose-1-phosphate.
Why Is GDP-mannose hydrolase activity Important in Cell Biology?
GDP-mannose hydrolase activity is important because it regulates the cellular concentration of GDP-mannose, a key nucleotide sugar donor for protein glycosylation and cell wall biosynthesis. By hydrolyzing GDP-mannose, the enzyme can influence the availability of mannose-1-phosphate and GMP, thereby affecting metabolic flux and signaling. In biotechnology, modulating this activity has been explored to enhance microbial L-fucose production. In human health, GDP-mannose metabolism is linked to cancer therapy response and congenital disorders of glycosylation, making this activity a potential target for therapeutic intervention.
• Regulates GDP-mannose pools, which are essential for protein glycosylation and cell wall integrity.
• Enables microbial L-fucose production through rational enzyme design.
• Suppresses homologous recombination repair in triple-negative breast cancer, potentiating antitumor immunity.
• Provides a model for unusual Nudix enzymes that cleave at carbon rather than phosphorus.
• Its metal-dependent mechanism informs studies of glycosyl hydrolase catalysis.
• Links to congenital disorders of glycosylation via GMPPB and lysosomal dysfunction.
• Impacts yeast cell wall mannoprotein synthesis and heterologous protein expression.
• Offers a target for metabolic engineering of nucleotide sugar pathways.
• Contributes to understanding of DNA repair modulation by nucleotide sugars.
• Serves as a paradigm for dissociative glycosyl hydrolysis mechanisms.
What Happens During GDP-mannose hydrolase activity?
Substrate binding and recognition
In simple terms: The enzyme grabs GDP-mannose and positions it for cleavage.
GDP-mannose hydrolase binds its substrate, GDP-mannose, through interactions with the guanine base and the phosphate groups, as revealed by structural studies of the Nudix enzyme. The enzyme shares homology with the MutT family, but its active site is adapted to accommodate the bulky mannose moiety. Kinetic studies show that substrate binding is followed by a conformational change that aligns the glycosidic bond for hydrolysis.
Metal ion coordination and activation
In simple terms: Metal ions help the enzyme break the bond.
The enzyme requires divalent metal ions, such as Mg2+ or Mn2+, for activity. Magnetic resonance and kinetic studies indicate that these metal ions activate a water molecule and stabilize the developing negative charge during catalysis. The metal ions are coordinated by conserved residues in the Nudix fold, and their removal abolishes hydrolysis.
Dissociative glycosyl cleavage
In simple terms: The bond breaks in a way that separates the sugar from the nucleotide.
The catalytic mechanism is dissociative, meaning the bond between mannose and GDP breaks before the water molecule attacks, forming an oxocarbenium-like transition state. This is unusual for Nudix enzymes, which typically cleave pyrophosphate bonds. Mutational and kinetic evidence supports this dissociative pathway, with the enzyme cleaving at carbon instead of phosphorus.
Product release and cellular impact
In simple terms: The products are released and affect the cell's metabolism.
After hydrolysis, GMP and mannose-1-phosphate are released. Mannose-1-phosphate can enter glycosylation pathways, while GMP contributes to nucleotide pools. In yeast, elevated GDP-mannose levels and changes in cis-prenyltransferase activity influence protein glycosylation in pmt mutants. In bacteria, the enzyme modulates GDP-mannose availability for L-fucose production.
Key Genes Involved in GO:0052751 GDP-mannose hydrolase activity
The following genes and proteins are directly or indirectly associated with GDP-mannose hydrolase activity and its metabolic context.
| Gene | Major Role | Research Relevance |
|---|---|---|
| E. coli gmm (formerly yffH) | Encodes GDP-mannose mannosyl hydrolase, the prototype Nudix enzyme | Model for mechanistic and structural studies |
| MutT | Homolog in E. coli, defines the Nudix family | Provides evolutionary context for gmm |
| GMPPB | Encodes GDP-mannose pyrophosphorylase B, synthesizes GDP-mannose | Mutations cause GMPPB-CDG with lysosomal dysfunction |
| PMT1-7 | Protein O-mannosyltransferases in yeast, use GDP-mannose | Studied in pmt mutants with altered GDP-mannose levels |
| cis-prenyltransferase | Enzyme affected by GDP-mannose levels in yeast | Linked to glycosylation and cell wall integrity |
| Cellobiohydrolase II (Trichoderma reesei) | Heterologous protein affected by glycosylation in pmt mutants | Model for protein expression in yeast |
| Nudix hydrolase family members | Superfamily of enzymes including GDP-mannose hydrolase | Broad family for comparative studies |
| GDP-mannose 4,6-dehydratase | Converts GDP-mannose to GDP-4-keto-6-deoxymannose for fucose synthesis | Target for L-fucose production |
| GDP-fucose synthase | Final step in L-fucose synthesis from GDP-mannose | Metabolic engineering target |
| Homologous recombination repair proteins (e.g., RAD51) | Affected by GDP-mannose suppression | Linked to antitumor immunity in TNBC |
| Acid alpha-glucosidase (GAA) | Lysosomal enzyme deficient in GMPPB-CDG | Readout for glycosylation defects |
| LAMP1 | Lysosomal marker affected in GMPPB-CDG | Assesses lysosomal dysfunction |
| GDP-mannose transporter (Vrg4 in yeast) | Transports GDP-mannose into Golgi | Indirectly affects substrate availability |
| Mannose-1-phosphate guanylyltransferase | Synthesizes GDP-mannose | Upstream of hydrolase activity |
| Phosphomannomutase | Converts mannose-6-phosphate to mannose-1-phosphate | Glycosylation pathway enzyme |
| Dolichol-phosphate mannose synthase | Uses GDP-mannose for glycosylation | Competes with hydrolase for substrate |
How Is GDP-mannose hydrolase activity Regulated?
GDP-mannose hydrolase activity is regulated at multiple levels. Substrate availability is controlled by GDP-mannose synthesis via GMPPB and consumption by glycosyltransferases. In yeast, elevated GDP-mannose levels in pmt mutants correlate with changes in cis-prenyltransferase activity, suggesting feedback regulation. Metal ion availability also modulates enzyme activity, as divalent cations are required for catalysis. In cancer cells, GDP-mannose levels influence homologous recombination repair, indicating that metabolic flux through this pathway can affect DNA repair capacity.
GDP-mannose hydrolase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| GMPPB | GMPPB-CDG with lysosomal dysfunction and GAA deficiency | Knockout or point-mutation in patient fibroblasts or iPSCs |
| GDP-mannose hydrolase (gmm) | Bacterial L-fucose production | Overexpression or knockout in E. coli |
| RAD51 | Homologous recombination repair in TNBC | Knockout in TNBC cell lines with GDP-mannose treatment |
| PMT1-7 | Yeast protein glycosylation and cell wall integrity | Knockout in Saccharomyces cerevisiae |
| GAA | Acid alpha-glucosidase deficiency in GMPPB-CDG | Knock-in of patient mutations in cell models |
GDP-mannose hydrolase activity and cancer
In triple-negative breast cancer, GDP-mannose suppresses homologous recombination repair and potentiates antitumor immunity. This suggests that modulating GDP-mannose levels, potentially through hydrolase activity, could sensitize tumors to DNA-damaging agents or immunotherapy. The mechanism involves altered nucleotide sugar metabolism affecting DNA repair pathways.
Congenital disorders of glycosylation
Mutations in GMPPB, which affect GDP-mannose synthesis, cause a congenital disorder of glycosylation (GMPPB-CDG) characterized by lysosomal dysfunction and acid alpha-glucosidase deficiency. Although GDP-mannose hydrolase activity itself has not been directly linked to CDG, the balance of GDP-mannose metabolism is critical for normal glycosylation.
Microbial pathogenesis and biotechnology
In bacteria, GDP-mannose hydrolase activity influences GDP-mannose pools, which are important for cell wall biosynthesis and virulence. Rational design of this enzyme has been explored for microbial L-fucose production, a valuable nutraceutical. In yeast, altered GDP-mannose levels affect protein glycosylation and heterologous protein expression.
From GDP-mannose hydrolase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the catalytic mechanism of GDP-mannose hydrolase? | Point mutation of active-site residues in E. coli gmm |
| How does loss of GDP-mannose hydrolase affect glycosylation? | Knockout in Saccharomyces cerevisiae or E. coli |
| Can GDP-mannose hydrolase activity be targeted for L-fucose production? | Overexpression of rationally designed enzyme in microbial hosts |
| Does GDP-mannose hydrolase influence DNA repair in cancer? | Knockout in triple-negative breast cancer cell lines |
| What is the role of metal ions in catalysis? | Point mutation of metal-coordinating residues |
| How does GMPPB-CDG affect lysosomal function? | Knock-in of patient mutations in iPSC-derived cells |
How to Study the GDP-mannose hydrolase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| HPLC-based enzyme assay | Production of GMP and mannose-1-phosphate | Kinetic characterization of purified enzyme |
| Coupled spectrophotometric assay | NADH consumption or product formation | High-throughput screening of inhibitors |
| X-ray crystallography | Three-dimensional structure of enzyme-substrate complex | Active-site mapping |
| NMR spectroscopy | Metal ion coordination and dynamics | Mechanistic studies |
| LC-MS metabolomics | GDP-mannose, GMP, mannose-1-phosphate levels | Cellular metabolic profiling |
| Lectin blotting | Glycosylation status of proteins | Yeast pmt mutant analysis |
| CRISPR knockout screening | Gene essentiality and synthetic lethality | Cancer therapy target discovery |
| Whole-exome sequencing | Mutations in GMPPB and related genes | Diagnosis of congenital disorders of glycosylation |
Enzymatic activity assays
GDP-mannose hydrolase activity is typically measured using coupled enzyme assays or HPLC to detect GMP and mannose-1-phosphate production. Kinetic parameters (Km, kcat) are determined by varying substrate concentrations and monitoring product formation. Metal dependence is assessed by adding or chelating divalent cations.
Structural biology
X-ray crystallography and NMR have been used to solve the structure of GDP-mannose hydrolase and its complexes with substrate analogs. These studies reveal the Nudix fold and the active-site architecture responsible for carbon cleavage. Mutational analysis combined with structural data identifies key catalytic residues.
Metabolic profiling
Mass spectrometry-based metabolomics can quantify GDP-mannose, GMP, and mannose-1-phosphate levels in cells or tissues. This approach is used to assess the impact of hydrolase activity on nucleotide sugar pools. In yeast, glycosylation changes are monitored by lectin blotting or mass spectrometry of glycans.
CRISPR screening and functional genomics
CRISPR knockout libraries can be used to identify genes that modulate GDP-mannose hydrolase activity or its downstream effects. In cancer cells, screens for homologous recombination repair defects can reveal synthetic lethal interactions with GDP-mannose metabolism. Bioinformatics analysis of genomic datasets can uncover associations between hydrolase expression and disease phenotypes.
How CRISPR Can Be Used to Study GO:0052751 GDP-mannose hydrolase activity
Knockout
CRISPR knockout of GDP-mannose hydrolase (e.g., E. coli gmm or yeast homologs) can reveal its role in GDP-mannose homeostasis, glycosylation, and cell wall integrity. In cancer cell lines, knockout of metabolic enzymes in the GDP-mannose pathway can sensitize cells to DNA-damaging agents. Knockout models are also used to study the enzyme's contribution to L-fucose production.
Point Mutation
Point mutations of catalytic residues (e.g., in the Nudix motif) can abolish hydrolase activity and help define the mechanism. Metal-coordinating residues can be mutated to assess their role in catalysis. Such mutants are valuable for distinguishing substrate binding from catalysis.
Knock-in
Knock-in of patient mutations in GMPPB or related genes can model congenital disorders of glycosylation. Tagged knock-in (e.g., GFP or FLAG) allows visualization and immunoprecipitation of the hydrolase in cells. Knock-in of reporter genes under the endogenous promoter can track expression dynamics.
Overexpression
Overexpression of GDP-mannose hydrolase can deplete GDP-mannose pools and impair glycosylation, providing a tool to study pathway flux. In biotechnology, overexpression of rationally designed variants enhances L-fucose production. Overexpression in cancer cells can suppress homologous recombination and potentiate immunotherapy.
How EDITGENE Supports GDP-mannose hydrolase activity Research
Researchers studying GDP-mannose hydrolase activity-related genes often need to determine whether a candidate gene is causally involved in metabolic regulation, glycosylation, or disease phenotypes. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models, enabling functional validation and mechanistic studies.
Contact EDITGENE today to design your custom CRISPR model for GDP-mannose hydrolase activity research.
Frequently Asked Questions About GDP-mannose hydrolase activity
What is GDP-mannose hydrolase activity?
GDP-mannose hydrolase activity (GO:0052751) is the catalysis of the reaction GDP-mannose + H2O = GMP + mannose-1-phosphate, cleaving the glycosidic bond at carbon rather than phosphorus.
What genes are involved in GDP-mannose hydrolase activity?
The prototype gene is E. coli gmm (formerly yffH), which encodes a Nudix enzyme homologous to MutT. In humans, GMPPB and related glycosylation genes influence GDP-mannose metabolism.
What is the mechanism of GDP-mannose hydrolase?
The enzyme uses a dissociative, metal-dependent mechanism to cleave GDP-mannose, forming an oxocarbenium-like transition state.
Is GDP-mannose hydrolase a Nudix enzyme?
Yes, it belongs to the Nudix hydrolase superfamily and shares homology with the MutT family, but it uniquely cleaves at carbon instead of phosphorus.
How is GDP-mannose hydrolase activity measured?
It is measured using HPLC or coupled enzyme assays that detect GMP and mannose-1-phosphate production, often with metal ion supplementation.
What diseases are linked to GDP-mannose hydrolase activity?
GDP-mannose metabolism is linked to triple-negative breast cancer through homologous recombination suppression and to GMPPB-CDG, a congenital disorder of glycosylation.
Can GDP-mannose hydrolase be used for L-fucose production?
Yes, rational design of GDP-mannose mannosyl hydrolase has been explored to enhance microbial L-fucose production.
What is the role of metal ions in GDP-mannose hydrolase?
Divalent metal ions such as Mg2+ or Mn2+ are required for catalysis, activating water and stabilizing the transition state.
How does GDP-mannose hydrolase affect glycosylation?
By hydrolyzing GDP-mannose, the enzyme reduces the pool available for glycosyltransferases, thereby influencing protein glycosylation and cell wall integrity.
What model systems are used to study GDP-mannose hydrolase?
Common models include E. coli, Saccharomyces cerevisiae, and cancer cell lines, using CRISPR knockout, point mutation, and overexpression.
Conclusion
GDP-mannose hydrolase activity (GO:0052751) is a unique Nudix enzyme activity that cleaves GDP-mannose at carbon, influencing nucleotide sugar pools, glycosylation, and cellular metabolism. Its roles in microbial L-fucose production, cancer DNA repair, and congenital glycosylation disorders highlight its broad biological and biomedical significance. Continued research using CRISPR models and metabolic profiling will further elucidate its mechanistic and therapeutic potential.
References
- 1. Fu C et al.. 2023. Rational design of GDP‑D‑mannose mannosyl hydrolase for microbial L‑fucose production.. Microb Cell Fact 22(1):56 PMID: 36964553
- 2. Ding JH et al.. 2024. Guanosine diphosphate-mannose suppresses homologous recombination repair and potentiates antitumor immunity in triple-negative breast cancer.. Sci Transl Med 16(728):eadg7740 PMID: 38170790
- 3. Gabelli SB et al.. 2004. Structure and mechanism of GDP-mannose glycosyl hydrolase, a Nudix enzyme that cleaves at carbon instead of phosphorus.. Structure 12(6):927-35 PMID: 15274914
- 4. Frick DN et al.. 1995. A novel GDP-mannose mannosyl hydrolase shares homology with the MutT family of enzymes.. J Biol Chem 270(41):24086-91 PMID: 7592609
- 5. Damiano C et al.. 2026. GMPPB-CDG Results in Lysosomal Dysfunction and Acid Alpha-Glucosidase Deficiency.. J Inherit Metab Dis 49(1):e70136 PMID: 41554119
- 6. Xia Z et al.. 2005. Mutational, structural, and kinetic evidence for a dissociative mechanism in the GDP-mannose mannosyl hydrolase reaction.. Biochemistry 44(25):8989-97 PMID: 15966723
- 7. Legler PM et al.. 2002. Kinetic and magnetic resonance studies of the role of metal ions in the mechanism of Escherichia coli GDP-mannose mannosyl hydrolase, an unusual nudix enzyme.. Biochemistry 41(14):4655-68 PMID: 11926828
- 8. Górka-Nieć W et al.. 2007. Protein glycosylation in pmt mutants of Saccharomyces cerevisiae. Influence of heterologously expressed cellobiohydrolase II of Trichoderma reesei and elevated levels of GDP-mannose and cis-prenyltransferase activity.. Biochim Biophys Acta 1770(5):774-80 PMID: 17343985
