Evidence for horizontal transfer of the EcoT38I restriction-modification gene to chromosomal DNA by the P2 phage and diversity of defective P2 prophages in Escherichia coli TH38 strains.

ABSTRACT: A DNA fragment carrying the genes coding for a novel EcoT38I restriction endonuclease (R.EcoT38I) and EcoT38I methyltransferase (M.EcoT38I), which recognize G(A/G)GC(C/T)C, was cloned from the chromosomal DNA of Escherichia coli TH38. The endonuclease and methyltransferase genes were in a head-to-head orientation and were separated by a 330-nucleotide intergenic region. A third gene, the C.EcoT38I gene, was found in the intergenic region, partially overlapping the R.EcoT38I gene. The gene product, C.EcoT38I, acted as both a positive regulator of R.EcoT38I gene expression and a negative regulator of M.EcoT38I gene expression. M.EcoT38I purified from recombinant E. coli cells was shown to be a monomeric protein and to methylate the inner cytosines in the recognition sequence. R.EcoT38I was p

SUBMITTER: Kita K 

PROVIDER: S-EPMC151499 | biostudies-literature | 2003 Apr

REPOSITORIES: biostudies-literature