PHD Transcription Factor Family
PHD proteins seem to be found universally in the nucleus, and their functions tend to lie in the
control of chromatin or transcription. Increasing evidence indicates that PHD fingers bind to
specific nuclear protein partners, for which they apparently use their loop 2 surface. Perhaps
each PHD finger has its own cognate nuclear ligand, much like RING fingers have their cognate E2
ligases. No doubt the list of specific PHD finger ligands will grow, and the set of these
ligands is likely to reveal whether PHD fingers have a common function in the nucleus.
The homeodomain (PHD) finger is a C4HC3 zinc-finger-like motif found in nuclear proteins thought
to be involved in chromatin-mediated transcriptional regulation. The PHD finger motif is
reminiscent of, but distinct from the C3HC4 type RING finger.
The function of this domain is not yet known but in analogy with the LIM domain it could be
involved in protein-protein interaction and be important for the assembly or activity of
multicomponent complexes involved in transcriptional activation or repression. Alternatively,
the interactions could be intra-molecular and be important in maintaining the structural
integrity of the protein. In similarity to the RING finger and the LIM domain, the PHD finger is
thought to bind two zinc ions.
65 predicated PHD TF peptide,
CDS, cDNA sequences;
blast HSP, and multiple sequence alignment in
Legume TFKB.
65 PHD domain peptide sequences with
alignment and phylogeny tree.
33 PHD protein and DNA
sequences with
annotations for soybean in PlantTFDB. Most are partial sequences.
Last updated by Dr. Jeff Chen on July 14, 2009.
