FIGURE 1.

Results of DNA sequence analysis of mutants from the N170X random library. The column on the left shows sequences of N170X mutants picked from the naive library before selection on ampicillin. These mutant sequences indicate that the Asn¹⁷⁰ position was randomized in the library and that there is no obvious bias among the sequences. The column on the right indicates sequences of mutants from the N170X library after selection for functional clones on agar plates containing 1 mg/ml ampicillin. The numbers in parentheses indicate the number of times the indicated codon was identified among the mutants sequenced.