IUBio Biosequences .. Software .. Molbio soft .. Network News .. FTP

Gating functions in protein networks

Dan dmb at mrc-dunn.cam.ac.uk
Mon Aug 4 09:16:50 EST 2003

> Sort of. The "LAC operon" (lactose operon) in E. coli is _almost_ an
> example of this, since the RNA polymerase won't transcribe the genes
> downstream of the LAC repressor site unless the CAP site is occupied
> and the LAC repressor site is NOT occupied. So the "logic" for the LAC
> operon is (CAP AND (NOT LAC)): 
> <http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/L/LacOperon.html>.
>>Do you mean one gene with two separate negative control mechanisms?
> Correct.

Cool, I guess there are many examples of this when one layer
of regulation is combined with others, like in systems which
respond to neural, hormonal and chemical factors.

Now what is that kinase called - I used to know the exact
regulatory circit - it is activated by glucagon, so maby
it is a phosphatase - adrenalin chops it in half....

I forget


perl -e '@A=qw(A T C G);for(1..10**6){print $A[rand(@A)]}' > \

>>(sorry I am not sure what NOR is)
> "NOR" is a contraction of "NOT OR," as in "NOT (a OR b)," as I wrote above.
> A "NOR" gate is "on" only when _neither_ of its inputs are "on," and "off"
> if either of its inputs are on. In the case of a gene, it is "on" if it can
> be transcribed to mRNA, and "off" if it is blocked from being transcribed;
> this could in principle be achieve by putting two "repressor" binding sites
> between it and its promoter.
> -- Gordon D. Pusch   
> perl -e '$_ = "gdpusch\@NO.xnet.SPAM.com\n"; s/NO\.//; s/SPAM\.//; print;'

More information about the Comp-bio mailing list

Send comments to us at biosci-help [At] net.bio.net