C2C2-GATA Transcription Factor Family
This domain uses four cysteine residues to coordinate a zinc ion. This domain binds to
DNA. Two GATA zinc fingers are found in the GATA transcription factors. However there
are several proteins which only contains a single copy of the domain.
A number of transcription factors (including erythroid-specific transcription factor
and nitrogen regulatory proteins), specifically bind the DNA sequence (A/T)GATA(A/G) in
the regulatory regions of genes. They are consequently termed GATA-binding
transcription factors. The interactions occur via highly-conserved zinc finger domains
in which the zinc ion is coordinated by 4 cysteine residues. NMR studies have shown the
core of the zinc finger to comprise 2 irregular anti-parallel beta-sheets and an
alpha-helix, followed by a long loop to the C-terminal end of the finger. The
N-terminal part, which includes the helix, is similar in structure, but not sequence,
to the N-terminal zinc module of the glucocorticoid receptor DNA-binding domain. The
helix and the loop connecting the 2 beta-sheets interact with the major groove of the
DNA, while the C-terminal tail wraps around into the minor groove. It is this tail that
is the essential determinant of specific binding. Interactions between the zinc finger
and DNA are mainly hydrophobic, explaining the preponderance of thymines in the binding
site; a large number of interactions with the phosphate backbone have also been
observed.Two GATA zinc fingers are found in the GATA transcription factors. However
there are several proteins that only contain a single copy of the domain.
GATA factors were first identified as proteins that interact with conserved WGATAR (W =
T or A; R = G or A) motifs involved in erythroid-specific gene expression in
vertebrates.
GATA factors are characterised by the presence of conserved, type-IV zinc-finger motifs
Animal factors typically contain two C-x2-Cx17-C-x2-C zinc-finger domains.The majority
of known fungal GATA factors contain a single C-x2-C-x17-C-x2-C finger with greatest
similarity to the carboxyl (C) terminal finger of animal GATA factors. Several examples
of fungal GATA factors containing a variant C-x2-C-x18-C-x2-C DNA-binding domain are
also known.
Examples of both C-x2-C-x17-Cx2-C (Type IVa) and C-x2-C-x18-C-x2-C (Type IVb) GATA
factors are found within fungi; animals onlycontain the former configuration, and
plants only the latter. Plant GATA factors typically contain a single zinc finger. The
Arabidopsis type-IV zinc-finger proteins may represent the previously defined family of
nuclear GATA-binding proteins implicated in light-responsive transcription.
66 predicted putative C2C2-GATA TF peptide,
CDS, and cDNA sequences;
blast HSP, and multiple sequence alignment in Soy TFKB.
GATA domain peptide sequences with alignment
and phylogeny tree.
12 C2C2-GATA protein
and
DNA sequences with
annotations for soybean in PlantTFDB. Most are partial sequences.
Last updated by Dr. Jeff Chen
on July 5, 2009.
