Noyer-Weidner M, Jentsch S, Kupsch J, Bergbauer M, Trautner T A
Gene. 1985;35(1-2):143-50. doi: 10.1016/0378-1119(85)90166-0.
The DNA methyltransferase (Mtase) genes of temperate Bacillus subtilis phages phi 3T, rho 11 and SP beta were cloned and expressed in Escherichia coli. Each gene specifies a 47-kDa1 protein, which modifies BsuR (GGCC) and Fnu4HI (GCNGC) target sequences. Transcription is controlled by phage promoters located on the cloned fragments. The direction of transcription and the approximate position of the Mtase genes were determined. DNA/DNA hybridization experiments revealed close structural relatedness of the phi 3T, rho 11 and SP beta genes. A significant degree of homology was also found among these genes and the Mtase gene of related phage SPR, which codes for an enzyme with different modification specificity. These results suggest a common ancestor of the different phage Mtase genes. Phage Z, the only BsuR-sensitive member of this phage group, lacks a modification gene, but contains regions homologous to sequences flanking the SPR, phi 3T, rho 11 and SP beta Mtase genes.
对温和型枯草芽孢杆菌噬菌体φ3T、ρ11和SPβ的DNA甲基转移酶（Mtase）基因进行了克隆，并在大肠杆菌中表达。每个基因编码一种47 kDa的蛋白质，该蛋白质可修饰BsuR（GGCC）和Fnu4HI（GCNGC）靶序列。转录由位于克隆片段上的噬菌体启动子控制。确定了转录方向和Mtase基因的大致位置。DNA/DNA杂交实验揭示了φ3T、ρ11和SPβ基因在结构上密切相关。在这些基因与相关噬菌体SPR的Mtase基因之间也发现了高度同源性，后者编码一种具有不同修饰特异性的酶。这些结果表明不同噬菌体Mtase基因有一个共同的祖先。噬菌体Z是该噬菌体组中唯一对BsuR敏感的成员，它缺乏修饰基因，但含有与SPR、φ3T、ρ11和SPβ Mtase基因侧翼序列同源的区域。
