Has anyone observed his5 or his6 strains made HIS+ by transformation
with HIS3? I have recent experience using a his5 strain. Since these three
genes are associated with completely different biochemical activities in the
histidine pathway, complementation seems unlikely. I don't think simple
reversion of his5 is the answer (although his5 and his6 will revert), since I
did a transformation involving a plasmid bearing HIS3 that gave 8-fold more
colonies than the control lacking plasmid. Does anyone have an explanation?
John
