Open AccessTranscriptional Regulation of the Clostridium cellulolyticum cip-cel Operon: a Complex Mechanism Involving a Catabolite-Responsive Element
Author(s) -
Laetitia Abdou,
Céline Boileau,
Pascale de Philip,
Sandrine Pagès,
Henri-Pierre Fiérobe,
Chantal Tardif
Publication year - 2008
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.01160-07
Subject(s) - catabolite repression , biology , operon , transcriptional regulation , transcription (linguistics) , gene , lac operon , gene cluster , biochemistry , transcription factor , gene expression , mutant , linguistics , philosophy
Thecip-cel cluster of genes plays an important role in the catabolism of the substrate cellulose byClostridium cellulolyticum . It encodes several key components of the cellulosomes, including the scaffolding protein CipC and the major cellulase Cel48F. All the genes of this cluster display linked transcription, focusing attention on the promoter upstream from the first gene,cipC . We analyzed the regulation of thecipC promoter using a transcriptional fusion approach. A single promoter is located between nucleotides −671 and −643 with respect to the ATG start codon, and the large mRNA leader sequence is processed at position −194. A catabolite-responsive element (CRE) 414 nucleotides downstream from the transcriptional start site has been shown to be involved in regulating this operon by a carbon catabolite repression mechanism. This CRE is thought to bind a CcpA-like regulator complexed with a P-Ser-Crh-like protein. Sequences surrounding the promoter sequence may also be involved in direct (sequence-dependent DNA curvature) or indirect (unknown regulator binding) regulation.