Fig. 4. Co-assembly of tagged 35S–labelled C–terminal KvLQT1 fragments. (A) Diagram illustrating protein constructs tagged with myc (mycC.T.354–676) or Xpress (xC.T.354–676). Full-length KvLQT1 protein is shown on top as in Figure 1A. (B) 35S–labelled myc- and Xpress-tagged C–termini were obtained by in vitro translation (Input). They were precipitated either with anti-Xpress antibodies (anti-Xpress) or with anti-myc antibodies (anti-myc). Proteins were separated by SDS–PAGE followed by autoradiography. Molecular weight markers are on the left. Lanes 1, 4 and 9 contained only xC.T.354–676, lanes 2, 6 and 7 only mycC.T.354–676, and lanes 3, 5 and 8 xC.T.354–676 and mycC.T.354–676 as starting material. (C) 35S–labelled mycC.T.354–676 was co-translated with xC.T.511–676, xC.T.511–620 or xC.T.511–589. Lanes 1–3 show the mycC.T.354–676/xC.T.354–676 proteins (Input), which were precipitated either with anti-Xpress antibodies (lanes 4–6) or with anti-myc antibodies (lanes 7–9). SDS–PAGE and autoradiography were as in (B).