Restriction digests of the clone give the following sizes (kb): XhoI--4.1; BglI--3.0, 1.1; AvaII--3.4, 0.7. Appropriate oligonucleotides can be inserted to change the sequences of the -10 and -35 reions of the promoter and thus set the promoter strength to any desired level. The vector can be used whenever it is necessary to maintain two plasmids within the same cell. ATCC 87499 and 87500 differ in -10 region promoter sequences: 87499--TACCTT; 87500--TATCAT. The sequence of -35 region promoter is TTGCAT. |
