MmoSTI restriction endonuclease, isolated from Morganella morganii infecting a tropical moth, Actias selene, cleaving 5′-|CCNGG-3′ sequences

Abstract

A type II restriction endonuclease, MmoSTI, from the pathogenic bacterium Morganella morganii infecting a tropical moth, Actias selene, has been detected and biochemically characterized, as a potential etiological differentiation factor. The described REase recognizes interrupted palindromes, i.e., 5′-CCNGG-3′ sequences and cleaves DNA leaving 5-nucleotide (nt) long, single-stranded (ss), 5′-cohesive ends, which was determined by three complementary methods: (i) cleavage of custom and standard DNA substrates, (ii) run-off sequencing of cleavage products, and (iii) shotgun cloning and sequencing of bacteriophage lambda (λ) DNA digested with MmoSTI. MmoSTI, the first 5′-CCNGG-3′ REase characterized from M. morganii, is a neoschizomer of ScrFI, which cleaves DNA leaving 1-nt long, ss, 5′-cohesive ends. It is a high-frequency cutter and can be isolated from easily cultured bacteria, thus it can potentially serve as a tool for DNA manipulations.