Disturibution and function of autoregulator jin streptomyces species producing antibiotics

采用Southern杂交技术对73种链霉菌进行了vbrA基因的检测，该基因编码弗吉尼亚链霉菌的转录抗菌剂NusG等效蛋白。S.griseus、S.lividans TK-21和s. coelicoles A3(2)等55株（75%）的菌株显示出明显的杂交信号，表明vbrA或vbrA同源物在链霉菌中分布广泛。通过对3种不同探针的杂交模式，即单独覆盖vbrA、单独覆盖下游基因rplK和同时覆盖vbrA-rplK的探针，将55株菌株分为4组。在I、II和III组（共50株）中，vbrA被发现与rplK相邻，这表明vbrA-rplK基因排列在链霉菌中是常见的，并且这些基因可能构成基因簇的一部分，编码转录和翻译装置的几个组分，就像在大肠杆菌中一样。

The presence of the vbrA gene encoding the transcriptional antiterminator NusG equvalent protein of Streptomyces virginiae was tested for in 73 Soteptomyces species by Southern hybridization. Fifty-five strains (75%) including S.griseus, S.lividans TK-21 and S.coelicolor A3(2) showed clear hybridization signals, indicating wide distribution of vbrA or vbrA homologs in Streptomyces species. With hybridization patterns against 3 different probes, i.e., probes covering vbrA alone, the downstream gene rplK alone, and both vbrA-rplK, the 55 strains were classified into 4 groups. In the group I, II and III (total 50 strains) vbrA was found to be adjcent to rplK, indicating that the gene arrangement vbrA-rplK is common in Streptomyces and that these gene may constitute a part of gene cluster encoding several components of the transcriptional and translational apparatus, as in Escherichia coli.