TECHNOLOGY BRIEF

For further information, contact Christine Brakel

Description: Plasmids for expression and over-expression of the Streptococcus pneumoniae restriction endonuclease enzymes DpnI and DpnII are provided as are gene constructs for the related methylase enzymes.

Commercial, Technical and Competitive Merit: DpnI and DpnII of S. pneumoniae cleave DNA at the same nucleotide sequence, 5'-GATC-3', but in a complementary fashion. The DpnI enzyme is unique among characterized restriction endonucleases in requiring methylated DNA sites for cleavage. DpnI activity requires that the sequence contain the N⁶-methyl form of the adenine re sidue and produces blunt-ended fragments after cleaving between me-A and T. DpnII is inactive on methylated DNA and produces sticky ends after cleaving 5' of the guanine residue. The plasmid constructs and gene cassettes can be used to produce large quantities of the active restriction endonuclease enzymes which are useful to molecular biologists. The restriction endonuclease genes can be used for a counter selection method (i.e., as a Adeath gene@) following gene transfer or gene activation.

Inventor: Sanford A. Lacks

Patent Status: U.S. Patent 4,960,707

License Status: Available on a non-exclusive basis.

Literature References: Lacks, et al., (1986) Cell 46, 993-1000.