Browse by author
Lookup NU author(s): Dr Leendert Hamoen
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
The competence transcription factor ComK plays a central role in competence development in Bacillus subtilis by activating the transcription of the K regulon. ComK-activated genes are characterized by the presence of a specific sequence to which ComK binds, a K-box, in their upstream DNA region. Each K-box consists of two AT-boxes with the consensus sequence AAAA-(N)5-TTTT, which are separated by a flexible spacer resulting in either two, three, or four helical turns between the starting nucleotides of the repeating AT-box units. In this study, the effects of potential determinants of ComK regulation in K-boxes were investigated by testing ComK's transcription activation and DNA-binding affinity on altered K-boxes with mutations either in the spacer between the AT-boxes or in the consensus sequence of the AT-boxes. The most striking result demonstrates the importance of the second thymine base in the AT-boxes. Mutation of this T into a guanine resulted in a threefold reduction in transcription activation and DNA binding by ComK. Transcription activation, as well as DNA binding, was almost completely abolished when both AT-boxes contained a T2-to-G mutation. This result was corroborated by in silico analyses demonstrating that a combination of mutations at the T 2 positions of both AT-boxes is not found among any ComK-activated K-boxes, indicating that at least one consensus T2 position is required to maintain a functional K-box. The results suggest an important structural role for T2 in ComK binding, probably by its specific position in the minor groove of the DNA. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
Author(s): Susanna KA, Mironczuk AM, Smits WK, Hamoen LW, Kuipers OP
Publication type: Article
Publication status: Published
Journal: Journal of Bacteriology
Year: 2007
Volume: 189
Issue: 13
Pages: 4718-4728
Print publication date: 01/07/2007
ISSN (print): 0021-9193
ISSN (electronic): 1067-8832
Publisher: American Society for Microbiology
URL: http://dx.doi.org/10.1128/JB.00281-07
DOI: 10.1128/JB.00281-07
PubMed id: 17468244
Altmetrics provided by Altmetric
