Rhizobium meliloti DctD, a sigma 54-dependent transcriptional activator, may be negatively controlled by a subdomain in the C-terminal end of its two-component receiver module.
Rhizobium meliloti DctD is believed to have three functional domains: an N-terminal, two-component receiver domain; and like other sigma 54-dependent activators, C-terminal and central domains for DNA binding and transcription activation. We have characterized a progressive series of N-terminal deletions of R. meliloti DctD. The N-terminal domain was not needed for binding the dctA upstream activation sequence. Only 25% of the C-terminal end of the receive domain was needed to significantly inhibit the central domain, and proteins lacking up to 60% of the N-terminal end of the receiver domain were 'inducible' in R. meliloti cells. We hypothesize that the N-terminal two-thirds of the DctD receiver domain augments and controls an adjacent subdomain for inhibiting the central domain.
Gu
B
B
Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802.
Lee
J H
JH
Hoover
T R
TR
Scholl
D
D
Nixon
B T
BT
D001426:Bacterial Proteins; D001665:Binding Sites; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D004269:DNA, Bacterial / Q000378:metabolism; D029382:Dicarboxylic Acid Transporters; D005813:Genes, Synthetic; D008956:Models, Chemical; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000235:genetics / Q000502:physiology*; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012808:Sigma Factor / Q000502:physiology*; D015398:Signal Transduction; D016962:Sinorhizobium meliloti / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D029382:Dicarboxylic Acid Transporters; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C073786:dctA protein, Sinorhizobium meliloti; C073787:DCTB protein, Sinorhizobium; C073788:dctD protein, Rhizobium meliloti; D011494:Protein Kinases