Structural analysis of the pseudaminic acid synthase PseI from Campylobacter jejuni.
Biochem Biophys Res Commun
; 635: 252-258, 2022 12 20.
Article
em En
| MEDLINE
| ID: mdl-36283338
ABSTRACT
Campylobacter jejuni PseI is a pseudaminic acid synthase that condenses the 2,4-diacetamido-2,4,6-trideoxy-l-altrose sugar (6-deoxy AltdiNAc) and phosphoenolpyruvate to generate pseudaminic acid, a sialic acid-like 9-carbon backbone α-keto sugar. Pseudaminic acid is conjugated to cell surface proteins and lipids and plays a key role in the mobility and virulence of C. jejuni and other pathogenic bacteria. To provide insights into the catalytic mechanism of PseI, we performed a structural study on PseI. PseI forms a two-domain structure and assembles into a domain-swapped homodimer. The PseI dimer has two cavities, each of which accommodates a metal ion using conserved histidine residues. A comparative analysis of structures and sequences suggests that the cavity of PseI functions as an active site that binds the 6-deoxy AltdiNAc and phosphoenolpyruvate substrates and mediates their condensation. Furthermore, we propose the substrate binding-induced structural rearrangement of PseI and predict 6-deoxy AltdiNAc recognition residues that are specific to PseI.
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Base de dados:
MEDLINE
Assunto principal:
Campylobacter jejuni
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article