FIG. 11.
β-Gal activity of the new expression vector, pTRK480, compared to those of pTRK392 (27) and subclone 566–888 (pTRK477). Subclone 566–888 was constructed in the high-copy-number promoter screening vector, pTRK390. pTRK392 is based on the low-copy-number replicon pSA3 and contains the phage φ31 origin of replication (ori31) (27) and lacZ.st under the control of P15A10. The new expression vector was constructed by replacing P15A10 with P566–862S. The β-Gal results shown represent the averages of at least three different assays, with each time point determination being performed in duplicate.