title: The Klebsiella pneumoniae PII protein (glnB gene product) is not absolutely required for nitrogen regulation and is not involved in NifL-mediated nif gene regulation.
abstract: The role of the Klebsiella pneumoniae PII protein (encoded by glnB) in nitrogen regulation has been studied using two classes of glnB mutants. In Class I mutants PII appears not to be uridylylated in nitrogen-limiting conditions and in Class II mutants PII is not synthesised. The effects of these mutations on expression from nitrogen-regulated promoters indicate that PII is not absolutely required for nitrogen control. Furthermore the uridylylated form of PII (PII-UMP) plays a significant role in the response to changes in nitrogen status by counteracting the effect of PII on NtrB-mediated dephosphorylation of NtrC. PII is not involved in the nif-specific response to changes in nitrogen status mediated by NifL.
authors.affiliation: AFRC Institute of Plant Science Research, University of Sussex, Brighton, UK.
authors.forename: A
authors.initials: A
authors.lastname: Holtel
authors.forename: M J
authors.initials: MJ
authors.lastname: Merrick
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002874:Chromosome Mapping; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation / Q000235:genetics; D051922:PII Nitrogen Regulatory Proteins; D013489:Suppression, Genetic
chemical_list: D001426:Bacterial Proteins; D051922:PII Nitrogen Regulatory Proteins; C404143:PIID regulatory protein, Bacteria; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen