{PDOC00564}
{PS00657; FORK_HEAD_1}
{PS00658; FORK_HEAD_2}
{PS50039; FORK_HEAD_3}
{BEGIN}
*******************************************
* Fork head domain signatures and profile *
*******************************************
It has been shown [1] that some eukaryotic transcription factors contain a
conserved domain of about 100 amino-acid residues, called the fork head
domain (but also known as a "winged helix"), which is involved in DNA-binding
[2]. Proteins known to contain this domain are listed below.
- Drosophila fork head protein (fkh). Fkh is probably a transcription factor
that regulates the expression of genes involved in terminal development.
- Drosophila protein crocodile (gene croc) [3], which is required for the
establishment of head structures.
- Drosophila proteins FD2, FD3, FD4, and FD5.
- Drosophila proteins sloppy paired 1 and 2 (slp1 and slp2) involved in
segmentation.
- Bombyx mori silk gland factor-1 (SGF-1) which regulates transcription of
the sericim-1 gene.
- Mammalian transcriptional activators HNF-3-alpha, -beta, and -gamma. The
HNF-3 proteins interact with the cis-acting regulatory regions of a number
of liver genes.
- Mammalian interleukin-enhancer binding factor (ILF). ILF binds to the
purine-rich NFAT-like motifs in the HIV-1 LTR and the interleukin-2
promoter. ILF may be involved in both positive and negative regulation of
important viral and cellular promoter elements.
- Mammalian transcription factor BF-1 which plays an important role in the
establishment of the regional subdivision of the developing brain and in
the development of the telencephalon.
- Human HTLF, a protein that binds to the purine-rich region in human T-cell
leukemia virus long terminal repeat (HTLV-I LTR).
- Mammalian transcription factors FREAC-1 (FKHL5, HFH-8), FREAC-2 (FKHL6),
FREAC-3 (FKHL7, FKH-1), FREAC-4 (FKHL8), FREAC-5 (FKHL9, FKH-2, HFH-6),
FREAC-6 (FKHL10, HFH-5), FREAC-7 (FKHL11), FREAC-8 (FKHL12, HFH-7), FKH-3,
FKH-4, FKH-5, HFH-1 and HFH-4.
- Human AFX1 which is involved in a chromosomal translocation that causes
acute leukemia.
- Human FKHR which is involved in a chromosomal translocation that causes
rhabdomyosarcoma.
- Xenopus XFKH1, a protein essential for normal axis formation.
- Caenorhabditis elegans lin-31; involved in the regulation of vulval cell
fates.
- Yeast HCM1, a protein of unknown function.
- Yeast FKH1.
- Yeast FKH2.
The fork domain is highly conserved. We have developed two patterns for its
detection. The first corresponds to the N-terminal section of the domain; the
second is a heptapeptide located in the central section of the domain.
-Consensus pattern: [KR]-P-[PTQ]-[FYLVQH]-S-[FY]-x(2)-[LIVM]-x(3,4)-[AC]-
[LIM]
-Sequences known to belong to this class detected by the pattern: ALL, except
for AFX1 and FKHR.
-Other sequence(s) detected in Swiss-Prot: NONE.
-Consensus pattern: W-[QKR]-[NSD]-[SA]-[LIV]-R-H
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in Swiss-Prot: NONE.
-Last update: December 2004 / Pattern and text revised.
[ 1] Weigel D., Jaeckle H.
"The fork head domain: a novel DNA binding motif of eukaryotic
transcription factors?"
Cell 63:455-456(1990).
PubMed=2225060
[ 2] Clark K.L., Halay E.D., Lai E., Burley S.K.
"Co-crystal structure of the HNF-3/fork head DNA-recognition motif
resembles histone H5."
Nature 364:412-420(1993).
PubMed=8332212
[ 3] Haecker U., Kaufmann E., Hartmann C., Juergens G., Knoechel W.,
Jaeckle H.
EMBO J. 14:5306-5317(1995).
{END}