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X-ray structure and characterization of a probiotic Lactobacillus rhamnosus Probio-M9 L-rhamnose isomerase.
Yoshida, Hiromi; Yamamoto, Naho; Kurahara, Lin Hai; Izumori, Ken; Yoshihara, Akihide.
Afiliación
  • Yoshida H; Department of Basic Life Science, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan. yoshida.hiromi@kagawa-u.ac.jp.
  • Yamamoto N; International Institute of Rare Sugar Research and Education, Kagawa University, Takamatsu, Kagawa, Japan. yoshida.hiromi@kagawa-u.ac.jp.
  • Kurahara LH; Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki, Kagawa, 761-0795, Japan.
  • Izumori K; Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-Cho, Kita-Gun, Kagawa, 761-0793, Japan.
  • Yoshihara A; International Institute of Rare Sugar Research and Education, Kagawa University, Takamatsu, Kagawa, Japan.
Appl Microbiol Biotechnol ; 108(1): 249, 2024 Mar 02.
Article en En | MEDLINE | ID: mdl-38430263
ABSTRACT
A recombinant L-rhamnose isomerase (L-RhI) from probiotic Lactobacillus rhamnosus Probio-M9 (L. rhamnosus Probio-M9) was expressed. L. rhamnosus Probio-M9 was isolated from human colostrum and identified as a probiotic lactic acid bacterium, which can grow using L-rhamnose. L-RhI is one of the enzymes involved in L-rhamnose metabolism and catalyzes the reversible isomerization between L-rhamnose and L-rhamnulose. Some L-RhIs were reported to catalyze isomerization not only between L-rhamnose and L-rhamnulose but also between D-allulose and D-allose, which are known as rare sugars. Those L-RhIs are attractive enzymes for rare sugar production and have the potential to be further improved by enzyme engineering; however, the known crystal structures of L-RhIs recognizing rare sugars are limited. In addition, the optimum pH levels of most reported L-RhIs are basic rather than neutral, and such a basic condition causes non-enzymatic aldose-ketose isomerization, resulting in unexpected by-products. Herein, we report the crystal structures of L. rhamnosus Probio-M9 L-RhI (LrL-RhI) in complexes with L-rhamnose, D-allulose, and D-allose, which show enzyme activity toward L-rhamnose, D-allulose, and D-allose in acidic conditions, though the activity toward D-allose was low. In the complex with L-rhamnose, L-rhamnopyranose was found in the catalytic site, showing favorable recognition for catalysis. In the complex with D-allulose, D-allulofuranose and ring-opened D-allulose were observed in the catalytic site. However, bound D-allose in the pyranose form was found in the catalytic site of the complex with D-allose, which was unfavorable for recognition, like an inhibition mode. The structure of the complex may explain the low activity toward D-allose. KEY POINTS • Crystal structures of LrL-RhI in complexes with substrates were determined. • LrL-RhI exhibits enzyme activity toward L-rhamnose, D-allulose, and D-allose. • The LrL-RhI is active in acidic conditions.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Isomerasas Aldosa-Cetosa / Lacticaseibacillus rhamnosus Límite: Humans Idioma: En Revista: Appl Microbiol Biotechnol Año: 2024 Tipo del documento: Article País de afiliación: Japón Pais de publicación: Alemania
Texto completo
Añadir a Mi BVS
Imprimir
XML
PubMed Links
Buscar en Google

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Isomerasas Aldosa-Cetosa / Lacticaseibacillus rhamnosus Límite: Humans Idioma: En Revista: Appl Microbiol Biotechnol Año: 2024 Tipo del documento: Article País de afiliación: Japón Pais de publicación: Alemania