[The determination of the site specificity of type-II restriction endonuclease in Streptomyces sp. 48].

The activity of restriction endonuclease which splits DNA of lambda and T7 phages into 8 fragments has been detected in the mycelium lysates of the 2-days culture of Streptomyces sp. 48. The fragments dimensions according to the data of agarose gel electrophoresis, coincide with those of AsuII--fragments of DNA of lambda and T7 phages. This allows the studied Ssp48 restrictase to be considered the isoschizomer of AsuII restriction endonuclease.