|
Sign In to gain access to subscriptions and/or personal tools.
|
THE BIOFILM CONCEPT: CONSEQUENCES FOR FUTURE PROPHYLAXIS OF ORAL DISEASES?
Anne Aamdal Scheie* and
Fernanda Cristina Petersen
Dept. of Oral Biology, Faculty of Dentistry, University of Oslo, PB 1052 Blindern, 0316 Oslo, Norway;
View larger version (17K):
[in this window]
[in a new window]
|
Figure 2. In a typical two-component signal transduction system, the transmembrane domain of the histine kinase recognizes a stimulus. Upon recognition, the histidine kinase catalyzes ATP-dependent autophosphorylation of a conserved histidine residue in the dimerization domain. The phosphoryl group is subsequently transferred to a conserved aspartate residue in the regulatory domain of the cognate response regulator. Phosphorylation activates the effector domain of the response regulator. The activated response regulator will then activate or repress transcription of specific target gene(s), promoting a specific response.
|
|
View larger version (86K):
[in this window]
[in a new window]
|
Figure 3b. Quorum-sensing systems in Gram-negative micro-organisms. The signal molecules ( )produced by the cells diffuse freely through the cell envelope. When a threshold level is reached, the signal molecules bind to and activate the transcriptional activator (TA). The signal-TA complex binds to target DNA and alters gene expression.
|
|
Critical Reviews in Oral Biology & Medicine, Vol. 15, No. 1,
4-12 (2004)
DOI: 10.1177/154411130401500102
 CiteULike  Complore  Connotea  Del.icio.us  Digg  Reddit  Technorati  Twitter What's this?
|
|
) is processed and exported by ABC-transporters. When a threshold level is reached, the extracellular peptides (
) bind to a histidine kinase receptor (HK) in the cell membrane, resulting in autophosphorylation of the histidine phosphotransferase domain. The phosphate (P) is transferred to the cognate response regulator (RR), which can then bind to target DNA and alter gene expression.