Synergistic @entity505 catabolite repression of the @entity3881 aconitase (citB) gene by @entity413 and a source of @entity15706 is dependent on DNA sequences located upstream of the gene. Mutations in a dyad symmetry element centered at position -66 and in a repeat of the downstream arm of the dyad symmetry at position -27 cause derepressed citB expression. In this work, a protein able to bind to a DNA fragment containing these elements was purified and identified. This protein, named CcpC (Catabolite control protein C), shares sequence similarity with members of the LysR family of transcriptional regulators. In addition to binding to the citB promoter, CcpC bound to the promoter of the citZ gene, which encodes the cell' @entity9855 @entity1792 synthase and is subject to @entity505 catabolite repression. In a ccpC null mutant, expression of both citB and citZ was derepressed in @entity413 - @entity1160 minimal medium, indicating that CcpC is a negative regulator of citB and citZ gene expression. DNase I footprinting experiments showed that CcpC binds to two sites within the citB promoter region, corresponding to the dyad symmetry and -27 elements. In the presence of @entity1792 , a putative inducer, only the dyad symmetry element was fully protected by CcpC. When the dyad symmetry element was mutated, CcpC was no longer able to bind to either the dyad symmetry or -27 elements. Repression of citB and citZ gene expression during anaerobiosis also proved to be mediated by CcpC.

CcpC, a novel regulator of the LysR family required for @entity413 repression of the citB gene in XXXX .

@entity9855 :: ('143350', 'Species') :: ['s major'] @entity1160 :: ('CHEBI:28300', 'Chemical') :: ['glutamine'] @entity15706 :: ('MESH:C029743', 'Chemical') :: ['2-ketoglutarate'] @entity1792 :: ('MESH:D019343', 'Chemical') :: ['citrate'] @entity505 :: ('MESH:D002244', 'Chemical') :: ['carbon'] @entity3881 :: ('1423', 'Species') :: ['Bacillus subtilis'] @entity413 :: ('MESH:D005947', 'Chemical') :: ['glucose']
@entity3881 :: (1423,Species) :: ['Bacillus subtilis']
