In <1iuvuiINNf0k at terminator.rs.itd.umich.edu> Mark A. Saper <saper at elmo.biop.umich.edu> write:
>I know about the periplasmic transport proteins ... these all have leader
>sequences. Is the protein that you are working with known to not have a
>leader sequence?
I have cloned and seqed a catalase gene which I purified the enzyme from periplasmic fraction from B.abortus which is a gram-negative bacterium. N-terminal amino acid sequence of the purified enzyme show no cleavable leader sequence. The a.a. sequence predicted by the nuceotide seq. also did not show any signal-like sequences. I checked the a.a. sequence of the periplasmic catalase of E.coli HP I(Biochem.Biophys.Res.Comm. 154:392-397) in the gene bank and could not find a leader sequence too. A recent mini
review in J.B. said membrane and periplasmic bacterial proteins used the uniformal secretion mechanism. In contrast, some of the extracellular proteins use self-promoted extracellular secretion mechanisms. I wonder if anyone has any idea?
