Putative Insertion Sequence

metzler at sara.cc.utu.fi metzler at sara.cc.utu.fi
Wed Jun 23 05:04:15 EST 1993

	I have some sequence data for a putative insertion sequence
which I don't quite understand. I thought I would post a message about
it and see if anybody has heard of something like this.
	The bacteria that I work with (Clavibacter xyli subsp. cynodontis)
contains a cryptic plasmid. A small region of this plasmid is repeated
many times (more than 50) on the chromosome. This suggests that it is
an insertion sequence, although probably not a transposon, given the
high copy number. I have now a little bit of sequence data (approx. 400 bp
from the plasmid sequence, and the same amount from a chromosomal copy.
Searching databases comes up with no matches. These two sequences are 
99% identical for most of their lengths. At the ends where they diverge,
they each contain different, direct tandem repeats (one is 7 bp, the other
is 15 bp, but not perfect, 12 bp match exactly). Nothing I have read in 
the literature describes anything like this. The direct repeats that are
seen normally at insertion sites are at opposite ends of the insertion sequence,
not tandemly at one end as these are. Has anyone ever seen or read about
anything like this? Of course, I need to continue sequencing, but with
no matches to anything in the database, I would like to have some evidence 
that what I am pursuing is actually likely to lead somewhere interesting.
	Thanks to anyone who can help.
	Mary Metzler	
Mary C. Metzler,                       |  Internet:  Metzler at Sara.CC.Utu.Fi  
Department of Botany,                  |  
University of Turku,                   |  This space to be witty until I think
Turku, SF-20500                        |  of something filled... oh yes.
Finland.                               |  a jelly donut.

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