A short GC-rich sequence involved in deletion formation of cloned DNA in E. coli.

: A spontaneous deletion probably caused by rec A independent recombination between short-direct repeat sequences was observed in pUC19 plasmid carrying a piece of Streptomyces genomic DNA after culturing in liquid medium. The deletion removed an unknown portion of the cloned DNA and the BamHI-EcoRI part of the multiple cloning site with an additional flanking 111 bp from the vector. At the junction a 13 bp GC-rich DNA sequence highly homologous to a known spontaneous deletion hotspot was found.