Friedberg, F. Mol Biol Rep (2011) 38: 213. doi:10.1007/s11033-010-0097-z
Genes for individual domains such as CH, lim, ankyrin, PH and RhoGAP, IQ motif, Ig_FLMN, spectrin, and EF hand probably existed in early evolution before there were plants, fungi or animals so that when we examine multidomain proteins in Arabidopsis, Saccharomyces, Dictyostelium or Homo Sapiens we encounter various combinations of such domains. While all of these four species express Fimbrin and EB1, the lists of CH containing multidomain proteins, however, differ in number and in type for each of them. There was no further great increase in the number of new single domain proteins. Still many new multidomain genes evolved—but far more so in metazoans—than in plants or fungi. In both plants and fungi only singlet CH domains but no doublets (other than those forming the Fimbrin quadruplet) were incorporated. That is in these two branches one finds no alpha actinin, dystrophin or filamin even though the individual building blocks (i.e. domains such as spectrin or IG-FLMN) were available in Arabidopsis. Possibly transposons create new chimeric multidomain genes by mixing and matching genes or gene fragments.
Clustal X alignment of the three Arabidopsis EB1 proteins (listed in Fig. 1). * in bold print indicates the presence of the CH domain (see the sequence AA 16-114) and of the EB1 domain (see the sequence LEK….ILY) (DOC 21 kb)
Multiple sequence Clustal X alignment for the single CH domains in Arabidopsis multidomain proteins and in Saccharomyces multidomain proteins. (They were listed in Figs. 1 and 2, respectively). In human singlet CH containing multidomain proteins the formula W(X)(17-29) G(X)11 P was proposed for identification of the CH domain (3). In Arabidopsis and Saccharomyces the formula can be slightly enlarged (with a few exceptions) to: W(X)4V or L or I, (X)12-23 G(X)3C(X)7P. The respective AA are indicated by bold type in this table (RTF 18 kb)