title: Molecular identification of the urea uptake system and transcriptional analysis of urea transporter- and urease-encoding genes in Corynebacterium glutamicum.
abstract: The molecular identification of the Corynebacterium glutamicum urea uptake system is described. This ABC-type transporter is encoded by the urtABCDE operon, which is transcribed in response to nitrogen limitation. Expression of the urt genes is regulated by the global nitrogen regulator AmtR, and an amtR deletion strain showed constitutive expression of the urtABCDE genes. The AmtR repressor protein also controls transcription of the urease-encoding ureABCEFGD genes in C. glutamicum. The ure gene cluster forms an operon which is mainly transcribed in response to nitrogen starvation. To confirm the increased synthesis of urease subunits under nitrogen limitation, proteome analyses of cytoplasmic protein extracts from cells grown under nitrogen surplus and nitrogen limitation were carried out, and five of the seven urease subunits were identified.
authors.affiliation: Institut für Biochemie der Universität zu Köln, Cologne, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Beckers
authors.forename: Anne K
authors.initials: AK
authors.lastname: Bendt
authors.forename: Reinhard
authors.initials: R
authors.lastname: Krämer
authors.forename: Andreas
authors.initials: A
authors.lastname: Burkovski
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D048230:Corynebacterium glutamicum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D015180:Electrophoresis, Gel, Two-Dimensional; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D009876:Operon; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D014508:Urea / Q000378:metabolism*; D014510:Urease / Q000235:genetics / Q000378:metabolism*; D000096982:Urea Transporters
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D003470:Culture Media; D026901:Membrane Transport Proteins; D009584:Nitrogen; D012097:Repressor Proteins; D014508:Urea; D014510:Urease; D000096982:Urea Transporters