FIG. 1.

Three types of motif arrangements. (A) Of the 75 dUTPases in this study, 62 consist of a single set of five conserved motifs (I to V). In addition to this common arrangement, two other variations are known. (B) All of the available alpha- and gammaherpesvirus sequences (six each) encode a dUTPase that has a single set of motifs but is twice as long as the common single arrangement. Motif III is conserved only in the amino portion of the protein, while motifs I, II, IV, and V are conserved in the carboxy portion. Possible remnants of motifs which imply a duplication of a single copy in the ancestor of these lineages and a subsequent loss of duplicate motifs are indicated by a question mark. The conservation of these remnants is variable within and between taxa (data not shown). Of the 12 available sequences, 10 have no amino acid residues in the position where the remnant of motif V would be; this is indicated by a dash (–). Sequences with this arrangement were analyzed in two sections: amino and carboxy. (C) The C. elegans sequence contains a triplicated dut colinearly transcribed and translated. Each copy of the triplicated protein has a complete set of the five motifs found in the common single copy arrangement of the gene. Each copy (amino, middle, and carboxy) was analyzed separately.