Construction and use of chimeric SPR/phi 3T DNA methyltransferases in the definition of sequence recognizing enzyme regions.

AUTOR(ES)

Balganesh, T S

RESUMO

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.

Documentos Relacionados

• High plasticity of multispecific DNA methyltransferases in the region carrying DNA target recognizing enzyme modules.
• Restriction and modification in Bacillus subtilis: DNA methylation potential of the related bacteriophages Z, SPR, SP beta, phi 3T, and rho 11.
• Human alpha satellite DNA--consensus sequence and conserved regions.
• Distribution of bacteriophage phi 3T homologous deoxyribonucleic acid sequences in Bacillus subtilis 168, related bacteriophages, and other Bacillus species.
• Nucleotide sequence of the spinach chloroplast tRNA(CAALeu) gene and its flanking regions.