Mei G Lei, Matthew A Jorgenson, Emily J Robbs, Ian M Black, Stephanie Archer-Hartmann, Sergei Shalygin, Parastoo Azadi, Chia Y Lee
{"title":"Characterization of Ssc, an <i>N</i>-acetylgalactosamine-containing <i>Staphylococcus aureus</i> surface polysaccharide.","authors":"Mei G Lei, Matthew A Jorgenson, Emily J Robbs, Ian M Black, Stephanie Archer-Hartmann, Sergei Shalygin, Parastoo Azadi, Chia Y Lee","doi":"10.1128/jb.00048-24","DOIUrl":null,"url":null,"abstract":"<p><p>Whole genome sequencing has revealed that the genome of <i>Staphylococcus aureus</i> possesses an uncharacterized 5-gene operon (SAOUHSC_00088-00092 in strain 8325 genome) that encodes factors with functions related to polysaccharide biosynthesis and export, indicating the existence of a new extracellular polysaccharide species. We designate this locus as <i>ssc</i> for staphylococcal surface carbohydrate. We found that the <i>ssc</i> genes were weakly expressed and highly repressed by the global regulator MgrA. To characterize Ssc, Ssc was heterologously expressed in <i>Escherichia coli</i> and extracted by heat treatment. Ssc was also conjugated to AcrA from <i>Campylobacter jejuni</i> in <i>E. coli</i> using protein glycan coupling technology (PGCT). Analysis of the heat-extracted Ssc and the purified Ssc-AcrA glycoconjugate by tandem mass spectrometry revealed that Ssc is likely a polymer consisting of <i>N</i>-acetylgalactosamine. We further demonstrated that the expression of the <i>ssc</i> genes in <i>S. aureus</i> affected phage adsorption and susceptibility, suggesting that Ssc is surface-exposed.</p><p><strong>Importance: </strong>Surface polysaccharides play crucial roles in the biology and virulence of bacterial pathogens. <i>Staphylococcus aureus</i> produces four major types of polysaccharides that have been well-characterized. In this study, we identified a new surface polysaccharide containing N-acetylgalactosamine (GalNAc). This marks the first report of GalNAc-containing polysaccharide in <i>S. aureus</i>. Our discovery lays the groundwork for further investigations into the chemical structure, surface location, and role in pathogenesis of this new polysaccharide.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11112989/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Bacteriology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1128/jb.00048-24","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/5/7 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Whole genome sequencing has revealed that the genome of Staphylococcus aureus possesses an uncharacterized 5-gene operon (SAOUHSC_00088-00092 in strain 8325 genome) that encodes factors with functions related to polysaccharide biosynthesis and export, indicating the existence of a new extracellular polysaccharide species. We designate this locus as ssc for staphylococcal surface carbohydrate. We found that the ssc genes were weakly expressed and highly repressed by the global regulator MgrA. To characterize Ssc, Ssc was heterologously expressed in Escherichia coli and extracted by heat treatment. Ssc was also conjugated to AcrA from Campylobacter jejuni in E. coli using protein glycan coupling technology (PGCT). Analysis of the heat-extracted Ssc and the purified Ssc-AcrA glycoconjugate by tandem mass spectrometry revealed that Ssc is likely a polymer consisting of N-acetylgalactosamine. We further demonstrated that the expression of the ssc genes in S. aureus affected phage adsorption and susceptibility, suggesting that Ssc is surface-exposed.
Importance: Surface polysaccharides play crucial roles in the biology and virulence of bacterial pathogens. Staphylococcus aureus produces four major types of polysaccharides that have been well-characterized. In this study, we identified a new surface polysaccharide containing N-acetylgalactosamine (GalNAc). This marks the first report of GalNAc-containing polysaccharide in S. aureus. Our discovery lays the groundwork for further investigations into the chemical structure, surface location, and role in pathogenesis of this new polysaccharide.
期刊介绍:
The Journal of Bacteriology (JB) publishes research articles that probe fundamental processes in bacteria, archaea and their viruses, and the molecular mechanisms by which they interact with each other and with their hosts and their environments.