Recombinant Desulfovibrio vulgaris 5-methylthioadenosine/S-adenosylhomocysteine deaminase (mtaD)

Introduction to Recombinant Desulfovibrio vulgaris 5-Methylthioadenosine/S-Adenosylhomocysteine Deaminase (mtaD)

Recombinant Desulfovibrio vulgaris 5-methylthioadenosine/S-adenosylhomocysteine deaminase (mtaD) is an engineered enzyme derived from the sulfate-reducing bacterium Desulfovibrio vulgaris. It catalyzes the hydrolysis of 5'-methylthioadenosine (MTA) and S-adenosylhomocysteine (SAH), serving as a critical component in the activated methyl cycle to recycle adenine and methionine . This recombinant protein is commercially available (e.g., MyBioSource.com at $995.00) , with applications spanning metabolic engineering, antimicrobial research, and biocatalysis .

Biochemical Role and Mechanism

mtaD operates in the SAM (S-adenosylmethionine)-dependent methylation pathway, where MTA and SAH are toxic byproducts. The enzyme hydrolyzes these nucleosides to release adenine and methionine, enabling their reuse in biosynthesis . Key functions include:

• Salvage of adenine and methionine: Recycling these metabolites prevents cellular toxicity and conserves resources.

• Regulation of methylation reactions: By removing MTA and SAH, mtaD prevents inhibition of SAM-dependent enzymes .

• Production of autoinducer-2 (AI-2): MTA degradation generates a quorum-sensing molecule critical for bacterial communication .

Mechanistic Insights:
The enzyme cleaves the glycosidic bond in MTA/SAH, releasing adenine and methylthioribose-1-phosphate (MTRP) or homocysteine, respectively . Structural studies of related enzymes (e.g., Borrelia burgdorferi MTN) suggest a conserved catalytic pocket with residues critical for substrate binding .

Sequence and Production

• Uniprot ID: A1VD37 .

• Sequence: Begins with MPLPCDTILQ... (full sequence available in ).

• Purity: >85% (SDS-PAGE) .

• Storage: Lyophilized form stable at -20°C/-80°C for 12 months .

Enzymatic Activity

Biocatalytic Applications

In a study on cis-α-irone synthesis, co-expression of mtaD with a methyltransferase (pMT10) enhanced production by ~6.5-fold compared to reactions without mtaD . This highlights its utility in metabolic engineering to optimize biosynthetic pathways.

Pathogenicity and Host Interactions

While mtaD itself is not directly implicated in virulence, D. vulgaris strains (including those expressing mtaD) have been linked to gut inflammation and colitis exacerbation in murine models . This underscores the broader role of Desulfovibrio species in microbiome dynamics.

Antimicrobial Target Potential

Inhibitors of MTA/SAH nucleosidases (e.g., in Borrelia) show promise as antimicrobials by disrupting methylation and quorum sensing . Though not directly tested for mtaD, similar strategies could target D. vulgaris in pathogenic contexts.