Fig. 1

Frameshift mutations in the Cl inhibitor gene. (A) The sequence from the reactive center coding region from the normal C1 inhibitor gene (nucleotides 17928−17977) is shown. The top sequence represents a tandem duplication aligned over the top of the duplicated sequence and the insertion site is denoted. The gray sequence represents a deletion of the normal sequence. The PstI site is identified by white text on a black background within the gray sequence. (B) The sequence from C1 inhibitor involved in the mutations can adopt a cruciform structure (nucleotides 1792m2−17969). The gray sequence represents the deleted sequence. The line overlies the duplicated sequence. White nucleotides on the black background demonstrate the PstI site. The capitalized sequence was cloned into pBR325. The sequence below this represents the sequence of pBR325 from nucleotide 4761. The EcoRI sites on either side of the imperfect repeat are slanting to indicate that they can engage in base-pairing contributing to the length of the stem-loop structure, and the additional EcoRI site generated by cloning is identified by the shadowed background.