title: Regulatory insights into the production of UDP-N-acetylglucosamine by Lactobacillus casei.
abstract: UDP-N-acetylglucosamine (UDP-GlcNAc) is an important sugar nucleotide used as a precursor of cell wall components in bacteria, and as a substrate in the synthesis of oligosaccharides in eukaryotes. In bacteria UDP-GlcNAc is synthesized from the glycolytic intermediate D-fructose-6-phosphate (fructose-6P) by four successive reactions catalyzed by three enzymes: glucosamine-6-phosphate synthase (GlmS), phosphoglucosamine mutase (GlmM) and the bi-functional enzyme glucosamine-1-phosphate acetyltransferase/ N-acetylglucosamine-1-phosphate uridyltransferase (GlmU). We have previously reported a metabolic engineering strategy in Lactobacillus casei directed to increase the intracellular levels of UDP-GlcNAc by homologous overexpression of the genes glmS, glmM and glmU. One of the most remarkable features regarding the production of UDP-GlcNAc in L. casei was to find multiple regulation points on its biosynthetic pathway: (1) regulation by the NagB enzyme, (2) glmS RNA specific degradation through the possible participation of a glmS riboswitch mechanism, (3) regulation of the GlmU activity probably by end product inhibition and (4) transcription of glmU.
authors: Laboratorio de Bacterias Lácticas y Probióticos, Departamento de Biotecnología de Alimentos; IATA-CSIC, Valencia, Spain.
authors: Jesús
authors: J
authors: Rodríguez-Díaz
authors: Antonio
authors: A
authors: Rubio-Del-Campo
authors: María J
authors: MJ
authors: Yebra
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism; D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D025461:Feedback, Physiological; D015964:Gene Expression Regulation, Bacterial; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) / Q000235:genetics / Q000378:metabolism; D007780:Lacticaseibacillus casei / Q000235:genetics* / Q000378:metabolism*; D060847:Metabolic Engineering; D010733:Phosphoglucomutase / Q000235:genetics / Q000378:metabolism; D020871:RNA Stability; D014158:Transcription, Genetic; D014537:Uridine Diphosphate N-Acetylglucosamine / Q000096:biosynthesis*
chemical_list: D001426:Bacterial Proteins; D014537:Uridine Diphosphate N-Acetylglucosamine; D000123:Acetyltransferases; C428383:glucosamine-1-phosphate acetyltransferase; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing); C020582:glucosamine-6-phosphate isomerase; D019747:Aldose-Ketose Isomerases; C097631:phosphoglucosamine mutase; D010733:Phosphoglucomutase