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Updated: Jun 18, 2026
08:37
The Application of Open Searching-based Approaches for the Identification of Acinetobacter baumannii O-linked Glycopeptides
Published on: November 2, 2021
Structural insights and therapeutic targets in Acinetobacter baumannii capsule biosynthesis
Woo Cheol Lee1, Junho Jeong1, Chae Yeong Lee1
1Department of Bioscience and Biotechnology, Konkuk University, Gwangjin-gu, Seoul, Republic of Korea.
FEBS Letters
|June 17, 2026
Summary
Hypervirulent Acinetobacter baumannii uses specific sugars for virulence. Targeting the ElaABC enzymes, crucial for producing these sugars, significantly reduced bacterial lethality and capsule production in mice.
Area of Science:
- Microbiology
- Structural Biology
- Biochemistry
Background:
- Gram-negative bacteria synthesize nonulosonic acids, nine-carbon sugars mimicking host sialic acids, potentially enhancing bacterial virulence.
- The K-locus 49 (KL49) capsule of hypervirulent Acinetobacter baumannii contains the nonulosonic acid 8-epi-Leg5,7Ac2, with ElaA, ElaB, and ElaC enzymes proposed to mediate its epimerization.
Purpose of the Study:
- To investigate the role of ElaABC enzymes in the virulence of hypervirulent KL49 Acinetobacter baumannii.
- To elucidate the structural basis of CMP-Leg5,7Ac2 synthesis and C8 epimerization mediated by ElaABC.
Main Methods:
- Identification and genetic manipulation (deletion) of KL49 Acinetobacter baumannii strains.
- In vivo studies using a mouse sepsis model to assess bacterial lethality.
- X-ray crystallography to determine the structures of ElaA, ElaB, and ElaC.
Main Results:
- A KL49 Acinetobacter baumannii strain causing lethal sepsis in mice was identified.
- Deletion of elaA, elaB, or elaC genes abolished bacterial lethality and significantly decreased capsule production.
- Structural analysis revealed conserved N-acetyl recognition mechanisms for CMP-Leg5,7Ac2 synthesis and C8 epimerization by ElaABC.
Conclusions:
- The ElaABC enzyme complex is essential for the virulence of hypervirulent KL49 Acinetobacter baumannii.
- ElaABC are key players in the synthesis and epimerization of nonulosonic acids contributing to bacterial capsule formation.
- ElaABC represent promising antivirulence targets for combating emerging hypervirulent KL49 Acinetobacter baumannii strains.
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