In the O1 strain of Klebsiella, the lipopolysaccharide (LPS) O-antigen is composed of D-galactan I and D-galactan II. Although the composition of the O1 antigen of Klebsiella was resolved more than two decades, the genetic locus involved in the biosynthesis of D-galactan II and the role of D-galactan II in bacterial pathogenesis remain unclear. Here, we report the identification of the D-galactan II-synthesizing genes by screening a transposon mutant library of an acapsulated Klebsiella pneumoniae O1 strain with bacteriophage. K. pneumoniae strain deleted for wbbY exhibited abrogated D-galactan II production; altered serum resistance and attenuation of virulence. Serologic analysis of K. pneumoniae clinical isolates demonstrated that D-galactan II was more prevalent in community-acquired pyogenic liver abscess (PLA)-causing strains than in non-tissue-invasive strains. WbbY homologs, WbbZ homologs, and lipopolysaccharide structures based on D-galactan II also were present in several Gram-negative bacteria. Immunization of mice with the magA-mutant (K(-) 1 O1) (that is, with a LPS D-galactan II-producing strain) provided protection against infection with an O1:K2 PLA strain. Our findings indicate that both WbbY and WbbZ homologs are sufficient for the synthesis of D-galactan II. D-galactan II represents an immunodominant antigen; is conserved among multiple species of Gram-negative bacteria and could be a useful vaccine candidate.
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http://dx.doi.org/10.3389/fmicb.2014.00608 | DOI Listing |
Int J Biol Macromol
April 2024
School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huai'an, Jiangsu 223003, China.
It is believed that polysaccharides will become a focal point for future production of food, pharmaceuticals, and materials due to their ubiquitous and renewable nature, as well as their exceptional properties that have been extensively validated in the fields of nutrition, healthcare, and materials. Sulfated polysaccharides derived from seaweed sources have attracted considerable attention owing to their distinctive structures and properties. The genus Codium, represented by the species C.
View Article and Find Full Text PDFPhysiol Plant
December 2023
The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, The University of Edinburgh, Daniel Rutherford Building, The King's Buildings, Edinburgh, UK.
All land-plant cell walls possess hemicelluloses, cellulose and anionic pectin. The walls of their cousins, the charophytic algae, exhibit some similarities to land plants' but also major differences. Charophyte 'pectins' are extractable by conventional land-plant methods, although they differ significantly in composition.
View Article and Find Full Text PDFInt J Biol Macromol
January 2024
Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry, Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, 130024, China. Electronic address:
Endo-1,4-β-galactanase is an indispensable tool for preparing prebiotic β-galacto-oligosaccharides (β-GOS) from pectic galactan resources. In the present study, a novel endo-1,4-β-galactanase (PoβGal53) belonging to glycoside hydrolase family 53 from Penicillium oxalicum sp. 68 was cloned and expressed in Pichia pastoris GS115.
View Article and Find Full Text PDFCarbohydr Res
July 2023
Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570, Japan; Green Bioscience Research Center, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570, Japan. Electronic address:
Type II arabinogalactans (AGs) are a highly diverse class of plant polysaccharides generally encountered as the carbohydrate moieties of certain extracellular proteoglycans, the so-called arabinogalactan-proteins (AGPs), which are found on plasma membranes and in cell walls. The basic structure of type II AG is a 1,3-β-D-galactan main chain with 1,6-β-D-galactan side chains. The side chains are further decorated with other sugars such as α-l-arabinose and β-d-glucuronic acid.
View Article and Find Full Text PDFNat Commun
April 2023
Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK.
Bacterial cell growth and division require the coordinated action of enzymes that synthesize and degrade cell wall polymers. Here, we identify enzymes that cleave the D-arabinan core of arabinogalactan, an unusual component of the cell wall of Mycobacterium tuberculosis and other mycobacteria. We screened 14 human gut-derived Bacteroidetes for arabinogalactan-degrading activities and identified four families of glycoside hydrolases with activity against the D-arabinan or D-galactan components of arabinogalactan.
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