22AP

Crystal structure of Bacillus cereus GmaR in complex with UDP-GlcNAc and Mg2+

22AP の概要

• エントリーDOI: 10.2210/pdb22ap/pdb
• 分子名称: GmaR, URIDINE-DIPHOSPHATE-N-ACETYLGLUCOSAMINE, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: glycosyltransferase, transferase
• 由来する生物種: Bacillus cereus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 47559.26

構造登録者

Oh, H.B.,Lee, S.J.,Yoon, S.I. (登録日: 2026-01-05, 公開日: 2026-04-22, 最終更新日: 2026-04-29)

主引用文献

Oh, H.B.,Lee, S.J.,Yoon, S.I.
Bacillus cereus GmaR glycosylates flagellin through a unique structural motif but is uncoupled from MogR regulation.
Int.J.Biol.Macromol., 360:151808-151808, 2026

PubMed Abstract: GmaR was identified in Listeria monocytogenes as an essential dual-function protein that regulates the MogR-mediated repression of flagellar gene expression and catalyzes the glycosylation of the flagellar protein flagellin. To elucidate the structural and molecular basis of GmaR function, we determined the crystal structure of Bacillus cereus GmaR (bcGmaR) and investigated its glycosyltransferase and regulatory activities through structure-based biochemical and mutational analyses. Unexpectedly, bcGmaR does not interact with MogR and is unlikely to function as a MogR regulator in contrast to L. monocytogenes GmaR. Instead, bcGmaR catalyzes Mg-dependent O-linked N-acetylglucosamine (GlcNAc) transfer to B. cereus flagellin, substantially increasing its thermostability. The N-terminal glycosyltransferase (GT) domain of bcGmaR adopts a three-layer GT-A type fold with a pocket, which accommodates Mg and the sugar donor UDP-GlcNAc through the canonical DxD and C-His motifs conserved among GT-A enzymes, as well as a bcGmaR-specific φHE motif located within a unique β-hairpin structure. Notably, the φHE motif is critical for catalysis, potentially by providing the catalytic base. In addition to the GT domain, the tetratricopeptide repeat domain is also required for full enzymatic activity. These findings highlight the functional divergence of GmaRs among bacterial species and underscore their unique catalytic features.

PubMed: 41937015
DOI: 10.1016/j.ijbiomac.2026.151808

実験手法

X-RAY DIFFRACTION (2.42 Å)