RHIZOBIUM-MELILOTI DCTD, A SIGMA(54)-DEPENDENT TRANSCRIPTIONAL ACTIVATOR, MAY BE NEGATIVELY CONTROLLED BY A SUBDOMAIN IN THE C-TERMINAL ENDOF ITS 2-COMPONENT RECEIVER MODULE
Bh. Gu et al., RHIZOBIUM-MELILOTI DCTD, A SIGMA(54)-DEPENDENT TRANSCRIPTIONAL ACTIVATOR, MAY BE NEGATIVELY CONTROLLED BY A SUBDOMAIN IN THE C-TERMINAL ENDOF ITS 2-COMPONENT RECEIVER MODULE, Molecular microbiology, 13(1), 1994, pp. 51-66
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 seri
es 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 receiver domain was needed to signif
icantly inhibit the central domain, and proteins lacking up to 60% of
the N-terminal end of the receiver domain were 'inducible' in R. melil
oti cells. We hypothesize that the N-terminal two-thirds of the DctD r
eceiver domain augments and controls an adjacent subdomain for inhibit
ing the central domain.