title: Construction and use of chimeric SPR/phi 3T DNA methyltransferases in the definition of sequence recognizing enzyme regions.
abstract: Multispecific DNA methyltransferases (Mtases) of temperate Bacillus subtilis phages SPR and phi 3T methylate the internal cytosine of the sequence GGCC. They differ in their capacity to methylate additional sequences. These are CCGG and CC(A/T)GG in SPR and GCNGC in phi 3T. Introducing unique restriction sites at equivalent locations within the two genes facilitated the construction of chimeric genes. These expressed Mtase activity at a level comparable to that of the parental genes. The methylation specificity of chimeric enzymes was correlated with the location of chimeric fusions. This analysis, which also included the use of mutant genes, showed that domains involved in the recognition of target sequences unique to each enzyme [CCGG, CC(A/T)GG or GCNGC] are represented by the central non-conserved parts of the proteins, whilst recognition of the sequence (GGCC), which is a target for both enzymes, is determined by an adjacent conserved region.
authors.affiliation: Max-Planck Institut für Molekulare Genetik, Berlin, Germany.
authors.forename: T S
authors.initials: TS
authors.lastname: Balganesh
authors.forename: L
authors.initials: L
authors.lastname: Reiners
authors.forename: R
authors.initials: R
authors.lastname: Lauster
authors.forename: M
authors.initials: M
authors.lastname: Noyer-Weidner
authors.forename: K
authors.initials: K
authors.lastname: Wilke
authors.forename: T A
authors.initials: TA
authors.lastname: Trautner
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology*; D001435:Bacteriophages / Q000201:enzymology*; D001483:Base Sequence; D002678:Chimera; D004262:DNA Restriction Enzymes; D015257:DNA-Cytosine Methylases; D004926:Escherichia coli / Q000235:genetics; D008780:Methyltransferases / Q000235:genetics*; D010957:Plasmids; D013045:Species Specificity; D013379:Substrate Specificity
chemical_list: D015257:DNA-Cytosine Methylases; D008780:Methyltransferases; D004262:DNA Restriction Enzymes