pMT660 is a temperature sensitive replication mutant of pIJ702. [1] Curable vector that can be used to insert and amplify cloned sequences into host chromosomal DNA. The 10.4 kb fragment from S. achromogenes contains the complete 8.8 kb amplifiable unit with 0.8 kb direct repeats at its termini. The unique BglII site is at one end of the 1.7 kb SphI/BglII fragment that determines spectinomycin resistance. When grown at 28C in S. lividans, the plasmid is present at high copy number and permits expression of spectinomycin resistance without amplification. When grown at 39C, the plasmid is cured and streptomycin resistance is lost except when AUD-Sar 1 sequences become integrated into the host chromosome where they undergo amplification. [3] The S. achromogenes fragment contains the following restriction sites (approximate kb from one end): MluI–1.7, 2.5, 3.0, 5.4, 5.9, 9.4, 10.2; SphI–2.1, 9.7; BglII–8.0. [2] Note: This material is cited in a U.S and/or other Patent and may not be used to infringe the patent claims. Deposited by: Wisconsin Alumni Research Foundation Hosts: Streptomyces lividans.