Methionine sulfoxide reductase A of Salmonella Typhimurium interacts with several proteins and abets in its colonization in the chicken

• Published in: Biochimica et biophysica acta. General subjects 2017-12, Vol.1861 (12), p.3238-3245
• Main Authors: Sarkhel, Ratanti, Rajan, Parvathy, Gupta, Ashish Kumar, Kumawat, Manoj, Agarwal, Pranjali, Shome, Arijit, Puii, Lalsang, Mahawar, Manish
• Format: Article
• Language: English
• Subjects: Animals; Chicken; Chickens - microbiology; Malate synthase; Malate Synthase - metabolism; Met-SO; Methionine Sulfoxide Reductases - physiology; Msr; S. Typhimurium; Salmonella typhimurium - enzymology
• ISSN: 0304-4165; 1872-8006
• DOI: 10.1016/j.bbagen.2017.09.014

Defending phagocyte generated oxidants is the key for survival of Salmonella Typhimurium (S. Typhimurium) inside the host. Met residues are highly prone to oxidation and convert into methionine sulfoxide (Met-SO). Methionine sulfoxide reductase (Msr) can repair Met-SO to Met thus restoring the function(s) of Met-SO containing proteins. Using pull down method we have identified several MsrA interacting proteins in the S. Typhimurium, one of them was malate synthase (MS). MS is an enzyme of glyoxylate cycle. This cycle is essential for survival of S. Typhimurium inside the host under nutrient limiting conditions. By employing in vitro cross-linking and blot overlay techniques we showed that purified MsrA interacted with pure MS. Treatment of pure malate synthase with H2O2 resulted in reduction of MS activity. However, MsrA along with thioredoxin-thioredoxin reductase system partially restored the activity of oxidized MS. Our mass spectrometry data demonstrated H2O2 mediated oxidation and MsrA mediated repair of Met residues in MS. Further in comparison to S. Typhimurium, the msrA gene deletion (∆msrA) strain showed reduced (60%) malate synthase specific activity. Oral inoculation with wild type, ∆msrA and ∆ms strains of S. Typhimurium resulted in colonization of 100, 0 and 40% of the poultry respectively. •Malate synthase (MS), an enzyme of glyoxylate shunt, is one of the targets of MsrA which was identified in S. Typhimurium.•MsrA mediated repair restored the activity of oxidized MS.•Mass spectrometry analysis indicates H2O2 mediated oxidation and MsrA mediated repair of Met residues in purified MS.•∆msrA and ∆ms strains show defective colonization in poultry caecum.