This vector is a high copy number, E.coli plasmid, 5258 bp in length.
The plasmid contain:
1 - the pMB1 replicon (Rep Origin 1) responsible for the replication of plasmid; this replicon is controlled by lactose promoter and, as a result, the pAlacZ-supF10 plasmid is stable in cells when media is supplemented with IPTG or lactose; if IPTG or lactose are absent in the media, the plasmid is rapidly lost by cells;
2 – the sequence encoding lactose repressor (lacI)
3 – the Ap(R) gene, coding for b-lactamase, that confers resistance to ampicillin;
4 – the region of E.coli lac operon containing a promoter Plac, lac repressor binding site and the 5’-terminal part of the lacZ gene encoding the modified N-terminal fragment of -galactosidase (-peptide). This fragment, whose synthesis can be induced by IPTG, is capable of intra-allelic (alpha) complementation with a defective form of -galactosidase encoded by the host (mutation delta(lacZ)M15). In the presence of IPTG, bacteria synthesize both fragments of the enzyme and form blue colonies on media with X-Gal.
5 – the sequence encoding suppressor tRNA (supF)
The map shows enzymes that can be used for insertion of foreign sequences.
The plasmid is fully compatible with those carrying the p15A replicon. This plasmid can be used for quick elimination of plasmids carrying pMB1 replicon but encoding different antibiotic resistance then that of pAlacZ-supF10 form cells. Using ampicillin-resistance, plasmid pAlacZ-supF10 can be used to substitute from cells other pMB1 replicon-carrying plasmid. Then, propagation of cells in IPTG- and ampicillin-free media may be used for fast elimination of plasmid pAlacZ-supF10 from cells as well.