DNA methyltransferase genes of Bacillus subtilis phages: structural relatedness and gene expression

Bacteriophage Orphan DNA Methyltransferases: Insights from Their Bacterial Origin, Function, and Occurrence

“…Temperate phages can pick up bacterial genes that flank the integration sites as a result of an excision error and transfer these genes to a new host, known as specialized transduction. Specialized transduction has been demonstrated in several studies including Brachyspira intermedia (81) and Bacillus phages (82). Temperate phages likely attained their orphan MTase-encoding genes in this way, as no homology was found between Bacillus temperate phages and their hosts (57).…”

Recombinant Derivatives of Bacillus Subtilis Phage Z Containing the DNA Methyltransferase Genes of Related Methylation-proficient Phages

“…Table 1 shows that compared to uncleaved DNA, partial or total in uitro restriction of the donor DNA reduced or abolished its potential to generate BsuR-resistant phages, although none of the enzymes used cleaves within the Mtase genes (Noyer-Weidner et al, 1983, and authors' unpublished observations). This finding can be rationalized on the basis of the size of the Mtase-gene-carrying fragments (Table 1) and, in the case of 43T and SPR, where mapping and/or sequencing data are available (Noyer-Weidner et al, 1985;Tran-Betcke et al, 1986), the location of the Mtase genes within these fragments. Phages obtained from singleplaque isolates proved to be recombinants since their resistance to BsuR restriction was stably acquired.…”

“…Hybridization to these plasmids proves the presence of the Mtase genes in the recombinant phages and reveals whether their immediate environment was involved in the recombination events. pBN 16 was also used as a probe against SPP/Z and pll/Z DNAs since the Mtase-coding fragments of 43T, SPP and pl 1 are extensively homologous (Noyer-Weidner et al, 1985).…”

Multispecific DNA methyltransferases from Bacillus subtilis phages

“…As calculated from the DNA sequence, the SPR methyltransferase gene encodes a 439-residue protein with a M , = 49826 [6]. An approximate M , of 47000 for the q3T, e l l and SPP enzymes has been determined by minicell expression studies and in an in vitro transcription/translation system [7].A set of SPR methyltransferase mutants has been isolated and the positions of the mutations localized in the methyltransferase coding region [6] represented in this study by the SPR26 methyltransferase [3], is affected in its ability to methylate all three sequences. Another group of mutants is altered in their ability to interact with either the GGCC sequence (SPR19) [4] or the CCGG sequence (SPR83) [6].…”

“…As calculated from the DNA sequence, the SPR methyltransferase gene encodes a 439-residue protein with a M , = 49826 [6]. An approximate M , of 47000 for the q3T, e l l and SPP enzymes has been determined by minicell expression studies and in an in vitro transcription/translation system [7].…”