Dear All:
This is not crystallography related and does not belong to this group,
but I would like to pose this to all who are working with proteins
expressed in an E. coli BL21 (DE3) or Rosetta. Is it possible for a
protein to be phosphorylated during expression? At least my
understanding was that post-translational modifications are not
possible in E. coli. However, recently we expressed a protein and
noticing that there are lot of potential tyrosine phosphorylation
sites, we checked the expressed protein on a gel using a stain that
detect phosphates. (Please do not say Are you crazy? Why would you
check.. etc). Lo and behold, there lights up the band. Hence my
question to you all. I could not google or mine from PubMed specific
references that exist regarding this. Please enlighten me.
Thanks a lot.
Also, I would like to take this opportunity to thank everybody for all
the help whenever ask some off-topic question like ths.
Subbu
