Structure of the K141 capsular polysaccharide produced by Acinetobacter baumannii isolate KZ1106 that carries KL141 at the chromosomal K locus

Carbohydr Res. 2024 Apr:538:109097. doi: 10.1016/j.carres.2024.109097. Epub 2024 Mar 24.

Abstract

The structure of the K141 type capsular polysaccharide (CPS) produced by Acinetobacter baumannii KZ1106, a clinical isolate recovered from Kazakhstan in 2016, was established by sugar analyses and one- and two-dimensional 1H and 13C NMR spectroscopy. The CPS was shown to consist of branched tetrasaccharide repeating units (K-units) with the following structure: This structure was found to be consistent with the genetic content of the KL141 CPS biosynthesis gene cluster at the chromosomal K locus in the KZ1106 whole genome sequence. Assignment of the encoded enzymes allowed the first sugar of the K unit to be identified, which revealed that the β-d-GlcpNAc-(1→3)-d-GlcpNAc bond is the linkage between K-units formed by the WzyKL141 polymerase.

Keywords: Acinetobacter baumannii; Capsular polysaccharide; K locus; K141; KL141.

MeSH terms

  • Acinetobacter baumannii* / chemistry
  • Acinetobacter baumannii* / genetics
  • Bacterial Capsules / chemistry
  • Magnetic Resonance Spectroscopy
  • Multigene Family
  • Polysaccharides / analysis
  • Polysaccharides, Bacterial / chemistry
  • Sugars

Substances

  • Polysaccharides
  • Sugars
  • Polysaccharides, Bacterial