title: Effect of T- and C-loop mutations on the Herbaspirillum seropedicae GlnB protein in nitrogen signalling.
abstract: Proteins of the PII family are found in species of all kingdoms. Although these proteins usually share high identity, their functions are specific to the different organisms. Comparison of structural data from Escherichia coli GlnB and GlnK and Herbaspirillum seropedicae GlnB showed that the T-loop and C-terminus were variable regions. To evaluate the role of these regions in signal transduction by the H. seropedicae GlnB protein, four mutants were constructed: Y51F, G108A/P109a, G108W and Q3R/T5A. The activities of the native and mutated proteins were assayed in an E. coli background constitutively expressing the Klebsiella pneumoniae nifLA operon. The results suggested that the T-loop and C-terminus regions of H. seropedicae GlnB are involved in nitrogen signal transduction.
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, C. Postal 19046, CEP 81531-990, Curitiba, PR, Brazil.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Bonatto
authors.forename: Emanuel M
authors.initials: EM
authors.lastname: Souza
authors.forename: Fábio O
authors.initials: FO
authors.lastname: Pedrosa
authors.forename: M Geoffrey
authors.initials: MG
authors.lastname: Yates
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Benelli
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D042803:Herbaspirillum / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism*; D051922:PII Nitrogen Regulatory Proteins; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D001616:beta-Galactosidase / Q000032:analysis
chemical_list: D001426:Bacterial Proteins; D051922:PII Nitrogen Regulatory Proteins; C404143:PIID regulatory protein, Bacteria; D001616:beta-Galactosidase; D009584:Nitrogen