8H2C

Crystal structure of the pseudaminic acid synthase PseI from Campylobacter jejuni

Summary for 8H2C

• Entry DOI: 10.2210/pdb8h2c/pdb
• Descriptor: Pseudaminic acid synthase, MANGANESE (II) ION (3 entities in total)
• Functional Keywords: pseudaminic acid synthase, tim barrel fold, type iii antifreeze-like domain, condensation reaction, biosynthetic protein
• Biological source: Campylobacter jejuni
• Total number of polymer chains: 4
• Total formula weight: 157174.97

Authors

Song, W.S.,Park, M.A.,Ki, D.U.,Yoon, S.I. (deposition date: 2022-10-05, release date: 2022-11-09, Last modification date: 2024-04-03)

Primary citation

Song, W.S.,Park, M.A.,Ki, D.U.,Yoon, S.I.
Structural analysis of the pseudaminic acid synthase PseI from Campylobacter jejuni.
Biochem.Biophys.Res.Commun., 635:252-258, 2022

PubMed 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.

PubMed: 36283338
DOI: 10.1016/j.bbrc.2022.10.050

Experimental method

X-RAY DIFFRACTION (2.9 Å)