FIG. 1.

Library construction and selection. (A) Vector construct and NLS insert sequences. The postinsertion DNA sequences are shown with the amino acid sequence resulting from the desired frame of insertion and the NLS is shown in bold type. X₁ and X₂ will depend on the 5 host nucleotides (N) duplicated during insertion. LTR, long terminal repeat; IRES, internal ribosome entry site; tTA, tetrecycline-controlled transactivator; TRE, tetracycline response element. (B) Schematic of library selection.