Structural Basis for Regulation and Specificity of Fructooligosaccharide Import in Streptococcus pneumoniae
نویسندگان
چکیده
Streptococcus pneumoniae is dependent on carbohydrate uptake for colonization and pathogenesis, and dedicates over a third of its transport systems to their uptake. The ability of the pneumococcus to utilize fructooligosaccharides (FOSs) is attributed to the presence of one of two types of FOS ATP-binding cassette (ABC) transporters. Strains encoding SfuABC are only able to utilize short-chain FOSs, while strains encoding FusABC can utilize both short- and long-chain FOSs. The crystal structures of the substrate-binding protein FusA in its open and closed conformations bound to FOSs, and solution scattering data of SfuA, delineate the structural basis for import of short- and long-chain FOSs. The structure of FusA identifies an EF hand-like calcium-binding motif. This is shown to be essential for translocation of FOSs in FusABC and forms the basis for the definition of a new class of substrate-binding proteins that regulate substrate translocation by calcium.
منابع مشابه
Functional and comparative genomic analyses of an operon involved in fructooligosaccharide utilization by Lactobacillus acidophilus.
Lactobacillus acidophilus is a probiotic organism that displays the ability to use prebiotic compounds such as fructooligosaccharides (FOS), which stimulate the growth of beneficial commensals in the gastrointestinal tract. However, little is known about the mechanisms and genes involved in FOS utilization by Lactobacillus species. Analysis of the L. acidophilus NCFM genome revealed an msm locu...
متن کاملExtracellular Zinc Competitively Inhibits Manganese Uptake and Compromises Oxidative Stress Management in Streptococcus pneumoniae
Streptococcus pneumoniae requires manganese for colonization of the human host, but the underlying molecular basis for this requirement has not been elucidated. Recently, it was shown that zinc could compromise manganese uptake and that zinc levels increased during infection by S. pneumoniae in all the niches that it colonized. Here we show, by quantitative means, that extracellular zinc acts i...
متن کاملCapsular Polysaccharide Expression in Commensal Streptococcus Species: Genetic and Antigenic Similarities to Streptococcus pneumoniae
Expression of a capsular polysaccharide is considered a hallmark of most invasive species of bacteria, including Streptococcus pneumoniae, in which the capsule is among the principal virulence factors and is the basis for successful vaccines. Consequently, it was previously assumed that capsule production distinguishes S. pneumoniae from closely related commensals of the mitis group streptococc...
متن کاملThe ABC transporter encoded at the pneumococcal fructooligosaccharide utilization locus determines the ability to utilize long- and short-chain fructooligosaccharides.
Streptococcus pneumoniae is an important human pathogen that requires carbohydrates for growth. The significance of carbohydrate acquisition is highlighted by the genome encoding more than 27 predicted carbohydrate transporters. It has long been known that about 60% of pneumococci could utilize the fructooligosaccharide inulin as a carbohydrate source, but the mechanism of utilization was unkno...
متن کاملAntimicrobial susceptibility and analysis of macrolide resistance genes in Streptococcus pneumoniae isolated in Hamadan
Objective(s): Macrolide resistant Streptococcus pneumoniae pose an emerging problem globally. The aim of this study was to investigate the prevalence of ermB and mefA genes (macrolide resistant genes) by polymerase chain reaction (PCR) method and to detect drug resistance patterns of S. pneumoniae isolated from clinical samples to macrolides and other antibiotic agents by E-test method. Materia...
متن کامل