Structure and phylogeny of yCCR4-related proteins. (A) Unrooted phylogenetic tree of the C-terminal region (hatched region in Fig. 1B) of 23 yCCR4-related protein sequences. The presented tree was constructed using the Neighbor-Joining method, with positions with gaps excluded and no correction for multiple substitutions (see Material and Methods). Bootstrap values representing the frequency of branching in 1000 replicates searches are indicated. The horizontal branch length and the scale indicate the percentage of amino acid substitutions from the nod. Vertical distances are arbitrary. See Table 1 for protein names and sequences. The four protein families which can be defined from the phylogenetic analyses are indicated on the right. (B) Structure of the yCCR4-related proteins. The C-terminal region conserved in all yCCR4-related proteins is represented by a hatched box. The highly conserved leucine-rich repeat (LRR) domain, found for animal members of the CCR4 family, is indicated by a black box. The yCCR4 activation domains, previously delineated in  are represented by grey boxes. The amino acid length of the proteins is indicated. (C) Intron/exon structure of the coding regions of the yCCR4-related genes. Sequences shown are those described in (B) for which genomic organization could be determined. Accession numbers or references for genomic sequences are listed in Table 1. Introns are represented by a line and exons by boxes with coding regions in grey. Sequences are drawn to scale, except large introns which are interrupted (but size indicated), introns of undetermined size (question mark in two human genes), and the non coding terminal exonic sequences (open boxes). Homologous intronic positions within each family are delineated, as well as the 5' bounderies (C-term) of the C-terminal regions, which have been aligned. The leucine-rich repeat (LRR) domains and the primers used to characterize the cDNAs of d.nocturnin, dCCR4 and ceCCR4 are indicated.