Detection of a disulphide bond and conformational changes in Shigella flexneri Wzy, and the role of cysteine residues in polymerase activity

Shigella flexneri Adapts to Niche-Specific Stresses through Modifications in Cell Envelope Composition and Decoration

“…These analyses identified classes of proteins at risk of DOC-mediated denaturation/aggregation, in which membrane proteins, including those involved with LPS biosynthesis, were identified. The major proteins involved with LPS production, namely those of the Wzy-dependent pathway, all possess multiple α-helical transmembrane (TM) domains, with the LPS Oag polymerase Wzy SF in particular containing 12 α-TM helices in addition to a key disulphide bondrendering it highly susceptible to DOC denaturation. , Further, due to its detergent-like properties, membrane lipids and the proteins within this environment are readily accessible to DOC. Collectively, these studies directly support our findings and fuel the proposition that DOC induces major disturbances of wildtype S.…”

“…The fluorescence of DPH-treated and untreated cells was then measured at 4 and 37 °C using spectrophotometry (BMG Labtech ClarioStar [Ex 360–20; Dichroic LP 410; Em 450–10]). Fluorescence anisotropy (A) was calculated as previously described …”

“…Fluorescence anisotropy (A) was calculated as previously described. 42 RNA Extraction and qRT-PCR. RNA was isolated from S. flexneri as previously described.…”

“…40 Wzy SF is known to interact closely with two polysaccharide copolymerase proteins, Wzz SF and Wzz pHS-2 , to modulate the production of two distinct Oag lengths, short-Oag (S-Oag; 10−17 RUs) and very long-Oag (VL-Oag; >90 RUs), respectively. 39,41,42 Importantly, appropriate regulation of the overall, and relative abundance of both Oag lengths is necessary for S. flexneri to maintain optimal virulence. 43,44 The present study aims to investigate the dynamics of the S. flexneri cell envelope, by specifically interrogating changes and adaptations following FA or bile salt exposure.…”

Characterizing the role of phosphatidylglycerol-phosphate phosphatases in Acinetobacter baumannii cell envelope biogenesis and antibiotic resistance

“…Samples containing cells were left to incubate with 0.5 mg.mL −1 proteinase K (Sigma-Aldrich) at 56℃. Silver staining of A. baumannii LOS and lipid extracts was performed using an established method ( Ascari et al, 2022 ). Densitometry analyses of lipid A bands were performed using Image Lab v6.1 software (Bio-Rad).…”