FIG. 4.
Expression cassettes constructed to study effect of carrier polypeptide on Xyn11A production. The overall structure of the expression cassettes was as described in the legend to Fig. 1. The amdS gene and the cel7A 3′ flanking region (not shown) were included as in the previous constructs. A sequence coding for the synthetic Kex2-like protein-processing signal RDKR, identical to that used in pALK948 and pALK1022, was included between the sequence coding for the carrier polypeptide and the xyn11A sequence, with the exceptions of pALK1118 and pALK1264. The expression cassette pALK1118 had the native man5A signal sequence (ss) cleaving signal and pALK1264 with an additional sequence coding for GQCGG preceding the Kex2 site. The constructs coding for the Man5A carrier (pALK1264 and pALK1022) had the man5A signal sequence, and the constructs coding for Cel6A CBD (pALK1283 to pALK1286) had the cel6A signal sequence. The numbers of native amino acids encoded by the carrier sequences, from M1 of the corresponding signal sequences, are shown. Cel6A CBD block A codes for the tail of the protein, B codes for the hinge, and B′ codes for the duplicated-hinge region. For a more detailed description, see Materials and Methods. fragm., fragment.