Recombinant Desulfovibrio vulgaris 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase (gpmA)

Introduction

Desulfovibrio vulgaris is a bacterium recognized as a potential pathogen due to clinical evidence . Desulfovibrio vulgaris can cause gut inflammation and aggravate colitis induced by DSS (dextran sulfate sodium) . The enzyme 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase (GpmA) plays a crucial role in the glycolysis and gluconeogenesis pathways . Phosphoglycerate mutases (PGMs) catalyze the transfer of a phosphate group between the second and third carbon atoms of glycerate, specifically the interconversion of 3-phosphoglycerate (3-PG) and 2-phosphoglycerate (2-PG) .

Genetics and Molecular Biology of Desulfovibrio vulgaris

Progress in the genetic manipulation of Desulfovibrio strains provides opportunities to explore electron flow pathways during sulfate respiration . Methods for engineering sulfate-reducing bacteria include homologous-recombination-mediated chromosomal manipulation of Desulfovibrio vulgaris . This involves a 'parts' based approach for suicide vector assembly, anaerobic culturing, antibiotic selection, electroporation-based DNA transformation, and tools for screening and verifying genetically modified constructs .

Homologous Recombination: Chromosomal modifications through homologous recombination require a suicide vector for D. vulgaris that can be propagated in E. coli and transferred to D. vulgaris by electroporation .

DNA Transformation: Foreign DNA (plasmid or linear) may be introduced into Desulfovibrio using conjugation or electroporation .

Role of GpmA in Virulence and Metabolism

A study of Acidovorax citrulli found that 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase is involved in virulence, carbohydrate metabolism, biofilm formation, twitching halo, and osmotic tolerance . A bdpmAc knockout mutant exhibited reduced virulence to watermelon, and could not grow with fructose or pyruvate as a sole carbon source . Proteomic analyses revealed that proteins involved in motility and wall/membrane/envelop biogenesis were differentially abundant . The mutant also exhibited decreased biofilm formation and twitching halo size, but a higher tolerance against osmotic stress .

GpmA Isozymes and Glycolytic Flux

Staphylococcus aureus possesses two copies of phosphoglycerate mutase: GpmI, which is Mn-dependent, and GpmA, which is Mn-independent and utilizes 2,3-bisphosphoglycerate as a catalytic cofactor . Expression of gpmA increased in response to CP, suggesting that the metal-independent variant promotes retention of glycolytic flux when metal-starved by the host .

Impact of Desulfovibrio vulgaris on Gut Inflammation

Transplantation of D. vulgaris into mice can cause gut inflammation, disrupt the gut barrier, and reduce levels of short-chain fatty acids (SCFAs) . D. vulgaris can also significantly augment DSS-induced colitis by exacerbating damage to the gut barrier and the secretion of inflammatory cytokines . D. vulgaris could markedly change GM composition, especially decreasing the relative abundance of SCFAs-producing bacteria, and stimulate the growth of Akkermansia muciniphila .

Effects on Gut Epithelial Morphology: DSS significantly disrupted gut epithelial morphology and reduced mucus secretion, with a subsequent rapid recovery . The combination of DV and DSS led to persistent epithelial damage and reduced mucus levels . Mice in the DV group exhibited damaged gut morphology and decreased mucus secretion .