The polysaccharide capsule surrounding bacterial cell plays an important role in pathogenesis of infections caused by the opportunistic pathogen Acinetobacter baumannii by providing protection from external factors. The structures of the capsular polysaccharide (CPS) produced by A. baumannii isolates and the corresponding CPS biosynthesis gene clusters are highly diverse, although many of them are related. Many types of A. baumannii CPSs contain isomers of 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acid (DTNA). Three of these isomers, namely acinetaminic acid (l-glycero-l-altro isomer), 8-epiacinetaminic acid (d-glycero-l-altro isomer), and 8-epipseudaminic acid (d-glycero-l-manno isomer), have not been found so far in naturally occurring carbohydrates from other species. In A. baumannii CPSs, DTNAs carry N-acyl substituents at positions 5 and 7; in some CPSs, both N-acetyl and N-(3-hydroxybutanoyl) groups are present. Remarkably, pseudaminic acid carries the (R)-isomer and legionaminic acid carries the (S)-isomer of the 3-hydroxybutanoyl group. The review addresses the structure and genetics of biosynthesis of A. baumannii CPSs containing di-N-acyl derivatives of DTNA.
Acinetobacter baumannii, capsular polysaccharide, nonulosonic acid, Bacterial polysaccharide, capsule, higher monosaccharide, acyl group
NCBI PubMed ID: 37072328Publication DOI: 10.1134/S0006297923020049Journal NLM ID: 0376536Publisher: Nauka/Interperiodica
Correspondence: Y.A. Knirel
Institutions: State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, 142279, Russia, Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 117913, Russia, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia, Branch of the Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry in Pushchino, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
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