The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 
 

Regulation of transcription initiation at the Escherichia coli nir operon promoter: a new mechanism to account for co-dependence on two transcription factors.

Expression from the Escherichia coli nir promoter is co-dependent on Fnr (a transcription factor triggered by oxygen starvation) and on NarL or NarP (transcription factors triggered by nitrite and nitrate ions). Fnr binds to a single DNA site centred between basepairs 41 and 42 upstream from the nir transcript start, whereas NarL and NarP bind to a site upstream, centred between basepairs 69 and 70. A novel mechanism to account for co-dependence on Fnr and NarL/NarP is suggested from experiments in which the spacing between the DNA sites for Fnr and NarL/NarP was altered. DNA sequence elements located upstream of the NarL/NarP-binding site are the targets for two or more proteins that act to repress Fnr-dependent activation of the nir promoter. This inhibition is counteracted by NarL or NarP. The model has been corroborated by the effects of several deletions and single base substitutions in the nir promoter upstream sequences: these deletions and substitutions prevent the binding of the repressor proteins. One of these repressors has been identified as the Fis protein, that binds to a site located 135-149bp upstream of the nir transcript start: the binding of Fis is suppressed by a single base substitution at position -146. The other repressor protein(s) have yet to be identified, but appear to bind downstream of the DNA site for Fis: binding is suppressed by a single base substitution at position -99.[1]

References

 
WikiGenes - Universities