FIG. 8.

Deletion analysis of CES2/ESP1 and sequence similarity to a subunit of the vaccinia virus capping enzyme. 2μ plasmid clones containing the complete ESP1 gene and deleted versions of ESP1 were constructed as described in Materials and Methods. The polypeptides encoded by these constructs are shown schematically in the figure. The clones are numbered according to the amino acid coordinates of the truncated ESP1 proteins they encode. The C-terminal 371-amino acid region homologous to nuclear division proteins cutl and bimB is shown as a hatched box. Regions of sequence similarity between the N-terminus of ESP1 and the D12 subunit of the vaccinia virus capping enzyme are depicted as bars. The sequences of the D12 and ESP1 proteins in these regions are aligned at the bottom. Amino acid identity is indicated by two dots (:); similarity is denoted by a single dot (.). The results of functional analyses of the clones are summarized on the left. ESP function refers to the ability of the plasmid-encoded gene to complement an espl::LEU2 mutation. CES activity refers to the experiment of Fig. 7, in which the clones were tested for multicopy suppression of ceg1−25.