A new site-specific endonuclease from Streptomyces lavendulae (SlaI)

A new restriction-like endonuclease, SlaI, was found and partially purified from Streptomyces lavendulae ATCC8664. This endonuclease cleaved bacteriophage lambda DNA at only one site, and cytosine-substituted bacteriophage T4 DNA at 16 sites. The recognition sequence was determined by using SlaI fragments of cytosine-substituted bacteriophage T4 DNA. The hexanucleotide recognized by SlaI endonuclease was (Formula: see text), with the sites of cleavage as indicated by the arrows. Therefore, SlaI endonuclease was an isoschizomer of XhoI endonuclease.