Alignment of nucleotide sequences of the tandem repeat units of RS I and RS II that lie within the CpY propeptide region of S. pombe ABP13 h− ade6-210 ura4-D18 (obtained from Fission Yeast Course, Cold Spring Harbor, N.Y.). Primers P1 (5′-TTGATGACGAGCGTCCCAAGC-3′), P2 (5′-CCTTCATGCTCCTCAAGCTCATGG-3′), P3 (5′-CCATGAGCTTGAGGAGCATGAAGG-3′), and P4 (5′-TTGCATGTTTTGCTCAGGACGTTC-3′) used for PCR analysis of the repeat regions are also indicated schematically. The code represents the code for each of the repeat units and indicates a specific sequence. The BstXI sites at which in the in-frame deletion pCPY-ID6 was constructed are underlined.