Solange,
Overlapping PCR should do it.
(x= any old sequence LYS2, get creative, use a restriction site for
later analysis!)
Round 1:
LYS 2 flank
35bp LYS2 flank
------> xxxxxxx------->
-------|---------------LYS2---------------|---------
<-------xxxxxxx <--------
Round 2:
------>
---------------xxxxxxx
xxxxxxx---------------
<-------
Trafo yeast with this PCR product:
35bp 35bp
--------------xxxxxxx------------
--------------xxxxxxx------------
Good luck,
Rich