Homology of the Erb1/Bop1
primary structure in eukaryotes. Organisms and sequence accession
nos are: Sce, S.cerevisiae (NP_013764);
Spo, Schizosaccharomyces pombe (S54549); Ath, Arabidopsis thaliana (AAD25679); Cel, Caenorhabditis
elegans (T26995); Dme, Drosophila melanogaster (T13579);
Mmu, Mus musculus (NP_038509); Hsa, Homo sapiens (BAA09473, incomplete sequence). Initial
alignment was obtained with ClustalX (34) and then manually edited
using GeneDoc (35). Black shading indicates identical residues and
conservative substitutions in all sequences; grey shading indicates
such residues in >50% sequences. WD repeats 1–5
were identified by a search against the Pfam database (36) in all
seven sequences. The WD1 repeat is the closest to the canonical
WD40 structure (5). Numbers within parentheses in each sequence
indicate lengths of small unique amino acid insertions and the N-terminal
domains, which are not conserved at the primary structure level
(see text).