Ja. Lowry et Wr. Atchley, Molecular evolution of the GATA family of transcription factors: Conservation within the DNA-binding domain, J MOL EVOL, 50(2), 2000, pp. 103-115
The GATA-binding transcription factors comprise a protein family whose memb
ers contain either one or two highly conserved zinc finger DNA-binding doma
ins. Members of this group have been identified in organisms ranging from c
ellular slime mold to vertebrates, including plants, fungi, nematodes, inse
cts, and echinoderms. While much work has been done describing the expressi
on patterns, functional aspects, and target genes for many of these protein
s, an evolutionary analysis of the entire family has been lacking. Herein w
e show that,only the C-terminal zinc finger (Cf) and basic domain, which to
gether constitute the GATA-binding domain, are conserved throughout this pr
otein family. Phylogenetic analyses of amino acid sequences demonstrate dis
tinct evolutionary pathways. Analysis of GATA factors isolated from vertebr
ates suggests that the six distinct vertebrate GATAs are descended from a c
ommon ancestral sequence, while those isolated from nonvertebrates (with th
e exception of the fungal AREA orthologues and Arabidopsis paralogues) appe
ar to be related only within the DNA-binding domain and otherwise provide l
ittle insight into their evolutionary history. These results suggest multip
le modes of evolution, including gene duplication and modular evolution of
GATA factors based upon inclusion of a class IV zinc finger motif. As such,
GATA transcription factors represent a group of proteins related solely by
their homologous DNA-binding domains. Further analysis of this domain exam
ines the degree of conservation at each amino acid site using the Boltzmann
entropy measure, thereby identifying residues critical to preservation of
structure and function, Finally, we construct a predictive motif that can a
ccurately identify potential GATA proteins.