Figure 4.

Design of primers for USER cloning with pMS26. Two choices of translation signal in the 5′-UTR are shown. The gene-specific sequence illustrated is of fnuDIIM. The underlined 21 bp of longer translation signal (LTS) is from the tacp regulatory region (34); the short signal (STS) is a truncation of it. The LTS and downstream primers illustrated are the same as primers 5 and 6 of Table 4; the STS construct was made but not used in this report. Fusion of lacZ to the signal as shown creates an RBS/ATG spacing of six, within the usual range of spacing (35); lacZ native spacing is seven (36).