(by aawara from pontiff-playground.org)
Fri Feb 29 19:25:33 EST 2008
In <u%Uxj.22$TP4.13 from newsfe07.lga>,
DK <dk from no.email.thankstospam.net> wrote:
> One thing I am confused about: since its substrate is
> in the nucleus, you'd expect it to be targeted to nucleus?
> And yet, the SNAP is a full lenght human cDNA and the
> company provides a special SNAP plasmid that targets
> the tag to nucleus. How come? Don't all enzymes that
> work on chromosomes tend to localize to nucleus?
Those are good observations and questions. I haven't used the tag,
but here's the information that I had received earlier. The SNAP tag
is a modified version of 6-O-methylguanine DNA methyltransferase, that
only recognizes para-substituted benzyl guanines. This substrate is
not recognized by the parental enzyme (and it is claimed, other cellular
The substrate (para-substituted benzyl guanine) is membrane permeable,
so it gets into cells very easily, and by the reaction you described,
modifies the SNAP tag with the para-substituent (which is typically
Since nucleotides/nucleosides are both cytoplasmic and nuclear,
presumably the substrate goes to where the SNAP-tagged protein is.
My concern is the same as yours. Does the tagged protein get dragged
to the nucleus?
Email: echo 36434455860060025978157675027927670979097959886449930P | dc
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