6BWC

X-ray structure of Pen from Bacillus thuringiensis

6BWC の概要

• エントリーDOI: 10.2210/pdb6bwc/pdb
• 分子名称: Polysaccharide biosynthesis protein CapD, NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, URIDINE-DIPHOSPHATE-N-ACETYLGLUCOSAMINE, ... (5 entities in total)
• 機能のキーワード: shout chain dehydrogenase, flagellin glycosylation, deoxy-sugar, biosynthetic protein
• 由来する生物種: Bacillus thuringiensis HD-771
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 241232.46

構造登録者

Delvaux, N.A.,Thoden, J.B.,Holden, H.M. (登録日: 2017-12-14, 公開日: 2018-01-17, 最終更新日: 2023-10-04)

主引用文献

Delvaux, N.A.,Thoden, J.B.,Holden, H.M.
Molecular architectures of Pen and Pal: Key enzymes required for CMP-pseudaminic acid biosynthesis in Bacillus thuringiensis.
Protein Sci., 27:738-749, 2018

PubMed Abstract: Bacillus thuringiensis is a soil-dwelling Gram positive bacterium that has been utilized as a biopesticide for well over 60 years. It is known to contain flagella that are important for motility. One of the proteins found in flagella is flagellin, which is post-translationally modified by O-glycosylation with derivatives of pseudaminic acid. The biosynthetic pathway for the production of CMP-pseudaminic acid in B. thuringiensis, starting with UDP-N-acetyl-d-glucosamine (UDP-GlcNAc), requires seven enzymes. Here, we report the three-dimensional structures of Pen and Pal, which catalyze the first and second steps, respectively. Pen contains a tightly bound NADP(H) cofactor whereas Pal is isolated with bound NAD(H). For the X-ray analysis of Pen, the site-directed D128N/K129A mutant variant was prepared in order to trap its substrate, UDP-GlcNAc, into the active site. Pen adopts a hexameric quaternary structure with each subunit showing the bilobal architecture observed for members of the short-chain dehydrogenase/reductase superfamily. The hexameric quaternary structure is atypical for most members of the superfamily. The structure of Pal was determined in the presence of UDP. Pal adopts the more typical dimeric quaternary structure. Taken together, Pen and Pal catalyze the conversion of UDP-GlcNAc to UDP-4-keto-6-deoxy-l-N-acetylaltrosamine. Strikingly, in Gram negative bacteria such as Campylobacter jejuni and Helicobacter pylori, only a single enzyme (FlaA1) is required for the production of UDP-4-keto-6-deoxy-l-N-acetylaltrosamine. A comparison of Pen and Pal with FlaA1 reveals differences that may explain why FlaA1 is a bifunctional enzyme whereas Pen and Pal catalyze the individual steps leading to the formation of the UDP-sugar product. This investigation represents the first structural analysis of the enzymes in B. thuringiensis that are required for CMP-pseudaminic acid formation.

PubMed: 29266550
DOI: 10.1002/pro.3368

実験手法

X-RAY DIFFRACTION (2.7 Å)