9ZAU

Pel polysaccharide deacetylase PelA from Bacillus cereus ATCC 10987

Summary for 9ZAU

• Entry DOI: 10.2210/pdb9zau/pdb
• Descriptor: Predicted membrane protein, putative, ZINC ION (3 entities in total)
• Functional Keywords: carbohydrate esterase, carbohydrate binding module (cbm), membrane protein
• Biological source: Bacillus cereus ATCC 10987
• Total number of polymer chains: 2
• Total formula weight: 134203.88

Authors

Shankara Subramanian, A.,Pfoh, R.,Howell, P.L. (deposition date: 2025-11-19, release date: 2026-05-20)

Primary citation

Subramanian, A.S.,Le Mauff, F.,Kitova, E.N.,Pfoh, R.,Panjalingam, M.,Wu, D.Y.,Gilbert, S.,Morrison, Z.A.,Jacobsen-Perez, C.A.,Razvi, E.,Nitz, M.,Codee, J.,Klassen, J.S.,Sheppard, D.C.,Howell, P.L.
Bacillus cereus PelA DA is a polysaccharide de-N-acetylase required for Pel-dependent biofilm formation.
J.Biol.Chem., :113122-113122, 2026

PubMed Abstract: Exopolysaccharides are key matrix determinants that provide structural integrity and regulate biomechanical properties of microbial biofilms. Biofilm exopolysaccharides often undergo modifications that determine their functional properties and localization. In B. cereus ATCC 10987, PelA expressed from the pelDEAFG operon is a putative deacetylase required for Pel-dependent biofilm formation. To understand the molecular basis of Pel deacetylation in B. cereus ATCC 10987, we determined the crystal structure of PelA to 2.51 Å. PelA adopts a distinct three-domain arrangement. We demonstrate in vitro that PelA deacetylates α-1,4-linked GalNAc substrates in a length-dependent manner and that the N-terminal domain functions as a carbohydrate binding module (CBM) capable of binding both GalNAc and partially deacetylated oligosaccharides. We found that the CBM domain together with the carbohydrate esterase (CE) domain forms an elongated carbohydrate binding cleft and that each domain is the founding member of two new CAZy families, CBMxx and CExx, respectively. Further, in vivo mutagenesis demonstrated that the catalytic activity of PelA is required for Pel biosynthesis in B. cereus ATCC 10987. Employing AlphaFold, we propose a model wherein the N-terminal transmembrane helix of PelA interacts with PelG. This interaction positions the protein to accept the polymer for deacetylation as it emerges from the cytoplasmic membrane. The work presented herein offers insight into the role of PelA in Pel biosynthesis and modification in B. cereus ATCC 10987.

PubMed: 42103218
DOI: 10.1016/j.jbc.2026.113122

Experimental method

X-RAY DIFFRACTION (2.51 Å)