GO:0070573 metallodipeptidase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070573 metallodipeptidase activity describes the metal-dependent hydrolysis of a dipeptide, where one or two metal ions activate a water nucleophile and charged side chains serve as metal ligands.
• The term covers enzymes such as VanX D-Ala-D-Ala dipeptidase and prolidase, which use divalent metal cofactors for peptide bond cleavage.
• Metal chelators such as 1,10-phenanthroline inhibit metallodipeptidase activity, confirming the essential role of metal ions in catalysis.
• Active-site residues including guanidinyl and carboxylate groups are critical for substrate binding and catalysis in metallodipeptidases.
• Metallodipeptidase activity is relevant to bacterial cell wall metabolism, antibiotic resistance, and peptide turnover in both prokaryotes and eukaryotes.
• CRISPR-based knockout, point mutation, and knock-in models enable precise dissection of metallodipeptidase gene function in disease and microbial physiology.
Description
Metallodipeptidase activity (GO:0070573) is a molecular function defined by the hydrolysis of a dipeptide using a metal-dependent catalytic mechanism. In this reaction, water acts as a nucleophile, one or two metal ions hold the water molecule in place, and charged amino acid side chains coordinate the metal ions. This activity is distinct from other peptidase classes because it requires divalent metal cofactors, typically zinc, manganese, or cobalt, for catalysis. The term is synonymous with metallo-exo-dipeptidase activity and metalloexodipeptidase activity, reflecting its exopeptidase mode of action on dipeptide substrates. Researchers study metallodipeptidase activity to understand bacterial cell wall remodeling, antibiotic resistance mechanisms, and peptide catabolism in higher organisms. The enzyme VanX, a D-Ala-D-Ala dipeptidase from enterococci, is a paradigm for this activity and is directly linked to vancomycin resistance. In mammals, prolidase is a metallodipeptidase that cleaves dipeptides containing proline or hydroxyproline, and its active site has been mapped using chemical modification. The dependence on metal ions is demonstrated by inhibition with chelators such as 1,10-phenanthroline, which blocks peptide breakdown in rumen bacteria and protozoa. Thus, GO:0070573 represents a conserved and medically relevant enzymatic function.
metallodipeptidase activity At A Glance
| GO ID | GO:0070573 |
|---|---|
| GO term | metallodipeptidase activity |
| Ontology | molecular_function |
| Synonym | metallo-exo-dipeptidase activity; metalloexodipeptidase activity |
| Definition | Catalysis of the hydrolysis of a dipeptide by a mechanism in which water acts as a nucleophile, one or two metal ions hold the water molecule in place, and charged amino acid side chains are ligands for the metal ions. |
| Major function | Metal-dependent cleavage of dipeptides into amino acids |
| Metal cofactors | Typically Zn2+, Mn2+, or Co2+ |
| Representative enzymes | VanX D-Ala-D-Ala dipeptidase, prolidase |
| Inhibitors | 1,10-phenanthroline and other metal chelators |
What Is GO:0070573?
GO:0070573 metallodipeptidase activity is defined as the catalysis of dipeptide hydrolysis by a mechanism in which water acts as a nucleophile, one or two metal ions hold the water molecule in place, and charged amino acid side chains are ligands for the metal ions. This definition, from the Gene Ontology, captures the essential metal-dependent catalytic strategy that distinguishes metallodipeptidases from other peptidases.
Why Is metallodipeptidase activity Important in Cell Biology?
Metallodipeptidase activity is important because it controls the final steps of peptide catabolism and is directly involved in bacterial cell wall biosynthesis and antibiotic resistance. The VanX enzyme, a metallodipeptidase, is essential for vancomycin resistance in enterococci by removing D-Ala-D-Ala dipeptides, thereby preventing vancomycin from binding to its target. In mammals, prolidase, a metallodipeptidase, participates in collagen turnover and proline recycling, and its active-site residues have been characterized. Inhibitors of metallodipeptidases such as 1,10-phenanthroline block peptide breakdown in complex microbial communities, highlighting their broad ecological and physiological roles. Because these enzymes require metal ions, they are also sensitive to metal availability and can be regulated by metal homeostasis. Understanding GO:0070573 is therefore relevant to antimicrobial drug discovery, metabolic engineering, and studies of peptide metabolism in health and disease.
• Metallodipeptidases are essential for bacterial cell wall remodeling and vancomycin resistance.
• They catalyze the final step in dipeptide breakdown, releasing free amino acids for recycling.
• Their activity depends on divalent metal ions such as Zn2+, Mn2+, or Co2+.
• Metal chelators like 1,10-phenanthroline inhibit these enzymes, providing a tool for functional studies.
• Active-site residues including guanidinyl and carboxylate groups are critical for catalysis.
• Prolidase, a mammalian metallodipeptidase, is involved in collagen metabolism and proline homeostasis.
• VanX homologs are found in diverse bacteria, including Streptomyces, Escherichia coli, and Synechocystis.
• Metallodipeptidase activity can be regulated by metal ion availability and enzyme expression.
• These enzymes are potential targets for novel antibiotics and enzyme inhibitors.
• CRISPR-based models allow precise interrogation of metallodipeptidase genes in disease and microbial systems.
What Happens During metallodipeptidase activity?
Substrate binding and metal coordination
In simple terms: The enzyme grabs a dipeptide and holds it next to metal ions that will help break it apart.
In the first step of metallodipeptidase activity, the dipeptide substrate binds to the active site, where one or two metal ions are already coordinated by charged amino acid side chains such as carboxylates and guanidinyl groups. These metal ions polarize the substrate and position it for hydrolysis. Mutational analysis of VanX has shown that active-site residues are critical for substrate binding and catalysis, and changes in these residues alter catalytic efficiency. The metal ions are typically zinc, manganese, or cobalt, as demonstrated for a zinc metallodipeptidase from mouse ascites tumor, where Mn2+ and Co2+ affect activity.
Water activation and nucleophilic attack
In simple terms: A water molecule is turned into a powerful attacker that cuts the peptide bond.
The metal ion(s) hold a water molecule in place and lower its pKa, converting it into a nucleophile. This activated water then attacks the carbonyl carbon of the peptide bond, forming a tetrahedral intermediate. The mechanism is metal-dependent, as shown by the inhibition of peptide breakdown by 1,10-phenanthroline, a metal chelator that removes the essential metal ions. The requirement for water as a nucleophile is a defining feature of GO:0070573.
Peptide bond cleavage and product release
In simple terms: The dipeptide is split into two amino acids, which are then released.
Following nucleophilic attack, the peptide bond is cleaved, and the two amino acid products are released from the active site. This exopeptidase action is characteristic of metallodipeptidases such as VanX, which specifically hydrolyzes D-Ala-D-Ala dipeptides. The reaction is irreversible under physiological conditions and completes the breakdown of dipeptides into free amino acids, which can be reused in metabolism.
Metal ion specificity and inhibition
In simple terms: Different metals can tune the enzyme, and chelators can shut it down.
Metallodipeptidases can use different metal ions for catalysis. For example, a zinc metallodipeptidase from mouse ascites tumor is affected by Mn2+ and Co2+, indicating metal exchange or competition. The activity of these enzymes is abolished by metal chelators such as 1,10-phenanthroline, which strip the metal ions from the active site. This sensitivity is a hallmark of metallodipeptidases and is used experimentally to classify them.
Key Genes Involved in GO:0070573 metallodipeptidase activity
The following genes and proteins are representative of metallodipeptidase activity (GO:0070573) and have been experimentally characterized in the literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| VanX (vanX) | D-Ala-D-Ala dipeptidase that removes dipeptide to confer vancomycin resistance | Model for metallodipeptidase mechanism and antibiotic resistance |
| VanX homologs in Streptomyces toyocaensis | Homolog of VanX with similar dipeptidase activity | Comparative studies of catalytic efficiency and stereoselectivity |
| VanX homolog in Escherichia coli | Homolog of VanX, potential dipeptidase | Bacterial peptide metabolism and resistance |
| VanX homolog in Synechocystis | Homolog of VanX, potential dipeptidase | Cyanobacterial peptide metabolism |
| Prolidase (PEPD) | Mammalian metallodipeptidase that cleaves proline-containing dipeptides | Active-site mapping and collagen metabolism |
| D-ala-D-Ala ligase (ddl) | Related enzyme in bacterial cell wall synthesis | Comparison with VanX for active-site studies |
| D-ala-D-Ala carboxypeptidase VanY | Related enzyme in vancomycin resistance | Comparison with VanX for mechanism |
| Zinc metallodipeptidase from mouse ascites tumor | Metal-dependent dipeptidase activity | Metal ion effects on activity |
| Rumen bacterial metallodipeptidases | Peptide breakdown in rumen | Inhibition by 1,10-phenanthroline |
| Presenilin1/2 (PSEN1/2) | Conditional knockout affects circadian rhythm and memory, with lncRNA changes | Potential link to peptide metabolism in neurodegeneration |
| PEPD (prolidase) | Hydrolyzes dipeptides with proline | Enzyme deficiency and collagen disorders |
| VanX (Enterococcus faecalis) | Vancomycin resistance dipeptidase | Structural and mutational studies |
| VanX (Enterococcus faecium) | Vancomycin resistance dipeptidase | Clinical resistance mechanisms |
| DppA (dipeptide binding protein) | Dipeptide transport | Substrate supply for metallodipeptidases |
| DppB (dipeptide permease) | Dipeptide transport | Substrate supply for metallodipeptidases |
| DppC (dipeptide permease) | Dipeptide transport | Substrate supply for metallodipeptidases |
| DppD (dipeptide permease) | Dipeptide transport | Substrate supply for metallodipeptidases |
| DppF (dipeptide permease) | Dipeptide transport | Substrate supply for metallodipeptidases |
How Is metallodipeptidase activity Regulated?
Metallodipeptidase activity is regulated at multiple levels. Metal ion availability directly controls catalysis, as shown by the effects of Mn2+ and Co2+ on a zinc metallodipeptidase from mouse ascites tumor. Enzyme expression can be regulated in response to cellular needs, such as during vancomycin resistance in enterococci, where VanX is induced. In rumen bacteria, peptide breakdown by metallodipeptidases is inhibited by 1,10-phenanthroline, indicating that metal chelation can modulate activity in complex microbial communities. Additionally, active-site modifications, such as chemical modification of guanidinyl and carboxylate groups in prolidase, can alter catalytic function. These regulatory mechanisms ensure that dipeptide hydrolysis is matched to metabolic demand and metal homeostasis.
metallodipeptidase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| VanX | Vancomycin resistance in enterococci | Knockout of vanX in Enterococcus faecalis; point mutations in active site |
| PEPD (prolidase) | Collagen metabolism disorders | Prolidase knockout or point mutation in mammalian cells |
| PSEN1/2 | Circadian rhythm and memory deficiency | Conditional knockout mice with lncRNA profiling |
| Rumen bacterial metallodipeptidases | Peptide breakdown in rumen | Inhibition by 1,10-phenanthroline in mixed cultures |
| Zinc metallodipeptidase from mouse ascites tumor | Metal-dependent peptide catabolism | Metal ion substitution and activity assays |
Antibiotic resistance
Metallodipeptidase activity is central to vancomycin resistance in enterococci. The VanX enzyme hydrolyzes D-Ala-D-Ala dipeptides, preventing vancomycin from binding to its target and allowing bacterial survival in the presence of the antibiotic. Homologs of VanX are found in other bacteria, including Streptomyces toyocaensis, Escherichia coli, and Synechocystis, suggesting broader roles in peptide metabolism and resistance. Inhibitors of metallodipeptidases could therefore serve as adjuvants to overcome resistance.
Collagen metabolism and prolidase deficiency
Prolidase (PEPD) is a mammalian metallodipeptidase that cleaves dipeptides containing proline or hydroxyproline, which are released during collagen breakdown. Its active site contains critical guanidinyl and carboxylate groups, as shown by chemical modification studies. Deficiencies in prolidase activity can lead to impaired collagen turnover and accumulation of proline-containing dipeptides, although the exact disease associations are beyond the scope of the cited literature.
Neurodegeneration and peptide metabolism
Presenilin1/2 conditional knockout mice exhibit circadian rhythm sleep disorders and time-of-day-dependent memory deficiency, with changes in long noncoding RNA expression. While presenilins are not metallodipeptidases, this model highlights the importance of peptide metabolism and metal homeostasis in neurodegeneration. Metallodipeptidases may contribute to the clearance of neurotoxic peptides, but direct evidence from the cited literature is limited.
From metallodipeptidase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the catalytic role of VanX active-site residues? | Point mutations in VanX (e.g., D123A) in E. coli |
| Does loss of metallodipeptidase activity affect vancomycin resistance? | Knockout of vanX in Enterococcus faecalis |
| How does prolidase deficiency affect collagen metabolism? | PEPD knockout or knock-in of patient mutations in mammalian cells |
| Can metal ion substitution alter metallodipeptidase activity? | Overexpression of zinc metallodipeptidase with Mn2+/Co2+ supplementation |
| What is the effect of metallodipeptidase inhibition on rumen peptide breakdown? | Treatment of rumen bacteria with 1,10-phenanthroline |
| Does presenilin loss affect peptide metabolism and behavior? | Conditional knockout of PSEN1/2 in mice with lncRNA profiling |
How to Study the metallodipeptidase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Enzymatic activity assay with dipeptide substrate | Hydrolysis rate and metal dependence | Characterization of metallodipeptidases |
| Site-directed mutagenesis | Effect of active-site mutations on catalysis | Mapping catalytic residues in VanX |
| Chemical modification | Identification of essential residues | Active-site mapping in prolidase |
| Metal chelation with 1,10-phenanthroline | Inhibition of peptide breakdown | Confirming metal dependence |
| RNA sequencing | Gene expression changes | Linking metallodipeptidases to pathways |
| Long noncoding RNA profiling | Noncoding RNA expression changes | Studying regulatory networks |
| Metal ion supplementation | Effect of Mn2+/Co2+ on activity | Metal specificity studies |
| Comparative genomics | Identification of VanX homologs | Evolutionary and functional studies |
Enzymatic activity assays
Metallodipeptidase activity is typically measured using dipeptide substrates and detecting the release of amino acids. Metal dependence can be tested by adding chelators such as 1,10-phenanthroline or by substituting metal ions like Mn2+ and Co2+. These assays are essential for confirming that a candidate enzyme belongs to GO:0070573.
Mutational analysis and active-site mapping
Site-directed mutagenesis of active-site residues, such as those in VanX, can reveal their roles in catalysis and substrate binding. Chemical modification of guanidinyl and carboxylate groups in prolidase has been used to locate active-site residues. These approaches provide mechanistic insights into metallodipeptidase function.
Gene expression profiling
RNA sequencing and long noncoding RNA profiling can identify changes in gene expression associated with metallodipeptidase activity, as shown in Presenilin1/2 conditional knockout mice. Such studies help link metallodipeptidase genes to broader cellular pathways and disease states.
Microbial inhibition studies
In complex microbial communities, the effect of metallodipeptidase inhibitors on peptide breakdown can be assessed by measuring peptide disappearance in the presence of 1,10-phenanthroline. This method is useful for studying the ecological role of metallodipeptidases in rumen and other environments.
How CRISPR Can Be Used to Study GO:0070573 metallodipeptidase activity
Knockout
CRISPR knockout of metallodipeptidase genes such as VanX or PEPD can abolish enzyme activity and reveal its role in antibiotic resistance or collagen metabolism. For example, knockout of vanX in Enterococcus faecalis would test its necessity for vancomycin resistance. In mammalian cells, PEPD knockout can model prolidase deficiency and its metabolic consequences.
Point Mutation
CRISPR point mutation can introduce specific amino acid substitutions in active-site residues of metallodipeptidases, such as those identified in VanX and prolidase. These models allow precise testing of catalytic mechanisms and metal coordination without altering the rest of the protein.
Knock-in
Knock-in of tagged or mutant metallodipeptidase genes enables visualization and functional analysis in native contexts. For example, a tagged VanX knock-in could be used to track its localization during vancomycin resistance. Similarly, knock-in of patient-derived PEPD mutations can model prolidase deficiency.
Overexpression
Overexpression of metallodipeptidases such as VanX or prolidase can be used to study their activity, substrate specificity, and effects on cellular metabolism. Overexpression in bacterial or mammalian cells can also facilitate biochemical purification and inhibitor screening.
How EDITGENE Supports metallodipeptidase activity Research
Researchers studying metallodipeptidase activity-related genes often need to determine whether a candidate gene is causally involved in dipeptide hydrolysis, antibiotic resistance, or metabolic disease. EDITGENE provides CRISPR-based cell model services that enable precise genetic manipulation of these genes, from complete knockout to single-base point mutations, knock-in of tags or mutations, and overexpression. These models are essential for validating enzyme function, dissecting catalytic mechanisms, and testing therapeutic hypotheses in relevant cellular contexts.
Contact EDITGENE today to design your custom CRISPR model for metallodipeptidase activity research.
Frequently Asked Questions About metallodipeptidase activity
What is metallodipeptidase activity?
Metallodipeptidase activity (GO:0070573) is the metal-dependent hydrolysis of a dipeptide, where water acts as a nucleophile and one or two metal ions hold the water in place.
What genes are involved in metallodipeptidase activity?
Key genes include VanX (D-Ala-D-Ala dipeptidase), prolidase (PEPD), and their homologs in bacteria such as Streptomyces, Escherichia coli, and Synechocystis.
What is the GO ID for metallodipeptidase activity?
The Gene Ontology ID for metallodipeptidase activity is GO:0070573.
How is metallodipeptidase activity regulated?
It is regulated by metal ion availability, enzyme expression, and active-site modifications, as shown for VanX and prolidase.
What diseases are associated with metallodipeptidase activity?
VanX-mediated metallodipeptidase activity is linked to vancomycin resistance, and prolidase deficiency affects collagen metabolism.
What inhibitors target metallodipeptidases?
Metal chelators such as 1,10-phenanthroline inhibit metallodipeptidase activity by removing essential metal ions.
What are the synonyms for metallodipeptidase activity?
Synonyms include metallo-exo-dipeptidase activity and metalloexodipeptidase activity.
Which metal ions are used by metallodipeptidases?
Common metal ions include Zn2+, Mn2+, and Co2+, as demonstrated for a zinc metallodipeptidase from mouse ascites tumor.
How can I study metallodipeptidase activity in the lab?
Enzymatic assays with dipeptide substrates, metal chelation, site-directed mutagenesis, and CRISPR knockout models are commonly used.
What CRISPR models are available for metallodipeptidase research?
EDITGENE offers knockout, point mutation, knock-in, and overexpression cell models for metallodipeptidase genes such as VanX and PEPD.
Conclusion
Metallodipeptidase activity (GO:0070573) is a conserved molecular function that uses metal ions to hydrolyze dipeptides, with critical roles in bacterial antibiotic resistance and mammalian peptide metabolism. The VanX enzyme and prolidase serve as key models for understanding its catalytic mechanism and regulation. Metal chelators and active-site mutations provide powerful tools to dissect this activity. CRISPR-based cell models from EDITGENE enable precise genetic interrogation of metallodipeptidase genes, accelerating research into their roles in health and disease.
References
- 1. Si Y et al.. 2023. Circadian rhythm sleep disorders and time-of-day-dependent memory deficiency in Presenilin1/2 conditional knockout mice with long noncoding RNA expression profiling changes.. Sleep Med 103:146-158 PMID: 36805914
- 2. Lessard IA et al.. 1999. Mutational analysis of active-site residues of the enterococcal D-ala-D-Ala dipeptidase VanX and comparison with Escherichia coli D-ala-D-Ala ligase and D-ala-D-Ala carboxypeptidase VanY.. Chem Biol 6(3):177-87 PMID: 10074467
- 3. Patterson EK et al.. 1975. The effect of Mn2+ and Co2+ on the activities of a zinc metallodipeptidase from a mouse ascites tumor.. Biochemistry 14(19):4261-6 PMID: 1237310
- 4. Lessard IA et al.. 1998. Homologs of the vancomycin resistance D-Ala-D-Ala dipeptidase VanX in Streptomyces toyocaensis, Escherichia coli and Synechocystis: attributes of catalytic efficiency, stereoselectivity and regulation with implications for function.. Chem Biol 5(9):489-504 PMID: 9751644
- 5. Mock WL et al.. 1991. Chemical modification locates guanidinyl and carboxylate groups within the active site of prolidase.. Biochem Biophys Res Commun 180(1):401-6 PMID: 1681807
- 6. Wallace RJ et al.. 1996. Inhibition by 1,10-phenanthroline of the breakdown of peptides by rumen bacteria and protozoa.. J Appl Bacteriol 80(4):425-30 PMID: 8849644
