Identification of SCP2 165 , a new SCP2‐derived plasmid of Streptomyces coelicolor A3(2)

Aims:  Characterization of SCP2 165 , a plasmid identified in the Gram‐positive bacterium Streptomyces coelicolor A3(2). Methods and Results:  Pulsed‐field gel electrophoresis (PFGE) of mycelia of a S. coelicolor strain embedded in low melting agarose revealed the presence of a plasmid. Restriction enzyme mapping and sequence analysis of a 2·1 kb fragment revealed that this plasmid could be SCP2. SCP2 and its spontaneous derivative SCP2* are self‐transmissible plasmids and have chromosome mobilizing ability (c.m.a.). SCP2* has a c. 1000‐fold increased c.m.a. compared with SCP2. Interestingly the plasmid, named SCP2 165 , shows a c.m.a. from 5 × 10 −2 to 1 × 10 −1 which is 50–100‐fold higher than that described for crosses involving SCP2*. Conclusions:  SCP2 165 is a SCP2 derivative plasmid with the highest c.m.a. so far described for SCP2 derivative plasmids. PFGE, under conditions we used, seems to be a fast way to identify large circular plasmids in Streptomyces strains. Significance and Impact of the Study:  Further knowledge of the SCP2 family may allow the construction of improved SCP2‐derived cloning vectors. SCP2 165 could be a potential tool for conjugational transfer of gene clusters between different Streptomyces species.