title: Glutamine metabolism of Corynebacterium glutamicum: role of the glutaminase GlsK.
abstract: Corynebacterium glutamicum is able to metabolize different nitrogen and carbon sources. In standard minimal media, ammonium and urea typically serve as nitrogen source and glucose or sucrose as carbon and energy source; however, amino acids might also play a role as nitrogen, carbon and energy source. In this study, the function of the putative glutaminase GlsK was investigated. A glsK deletion strain showed impaired growth with L-glutamine as carbon and energy source, while growth was improved upon glsK overexpression. GlsK possesses a carboxy-terminal domain that seems to be restricted to Corynebacterium species. A truncated GlsK lacking this extension led to faster growth, indicating a regulatory function of this domain. In fact, GlsK activity is regulated in a pH-dependent manner depending on the carboxy-terminal extension, and is positively influenced by cAMP. Furthermore, the C-terminal extension seems to be important for oligomerization of GlsK.
authors.affiliation: Department of Biology, Microbiology Division, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Buerger
authors.affiliation: Department of Biology, Microbiology Division, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Rehm
authors.affiliation: Department of Biology, Microbiology Division, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Grebenstein
authors.affiliation: Department of Biology, Microbiology Division, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany andreas.burkovski@fau.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Burkovski
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D017353:Gene Deletion; D016680:Genome, Bacterial / Q000235:genetics; D005972:Glutaminase / Q000235:genetics* / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism*
chemical_list: D064751:Ammonium Compounds; D005973:Glutamine; D005972:Glutaminase
keywords: ammonium assimilation; glutamate production; nitrogen assimilation