o54-dependent transcriptional activators such as Escherichia coli NtrC, Rhizobium meliloti NifA, and Rhizobium leguminosarum DctD share similar central and carboxy-terminal domains but differ in the structure and function of their amino-terminal domains. We have deleted the amino-terminal and carboxy-terminal domains of R. leguminosarum DctD and have demonstrated that the central domain of DctD, like that of NifA, is transcriptionally competent. The high degree of similarity among the central domains of a54-dependent activators (5, 8, 15) and the demonstration that the isolated central domain of Rhizobium meliloti NifA is capable of activating transcription (9) suggest that the central domain is responsible for transcriptional activation. Rhizobium leguminosarum DctD is a o-54-dependent activator, with central and carboxy-terminal domains similar to those of NifA, NtrC, and other c4-dependent activators (16). DctD is also the regulatory partner in a two-component system that regulates transcription of dctA, a gene encodin
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.