| Literature References | 1. WEIGEL, D., JURGENS, G., KUTTNER, F., SEIFERT, E. AND JACKLE, H.
The homeotic gene fork head encodes a nuclear protein and is expressed in
the terminal regions of the Drosophila embryo.
CELL 57 645-658 (1989).
2. CLARK, K.L., HALAY, E.D., LAI, E. AND BURLEY, S.K.
Co-crystal structure of the HNF-3/fork head DNA-recognition motif resembles
histone H5.
NATURE 364 412-420 (1993).
3. HACKER, U., GROSSNIKLAUS, U., GEHRING, W.J. AND JACKLE, H.
Developmentally regulated Drosophila gene family encoding the fork head
domain.
PROC.NATL.ACAD.SCI.U.S.A. 89 8754-8758 (1992).
|
| Documentation | The fork head protein of Drosophila, a transcription factor that promotes
terminal rather than segmental development, contains neither homeodomains
nor zinc-fingers characteristic of other transcription factors [1]. Instead,
it contains a distinct type of DNA-binding region, containing around 100
amino acids, which has since been identified in a number of transcription
factors (including Drosophila FD1-5, mammalian HNF-3, human HTLF, yeast
HCM1, etc.). This is referred to as the fork head domain [1-3].
The fork head domain binds B-DNA as a monomer [2], but shows no similarity
to previously identified DNA-binding motifs. Although the domain is found
in several different transcription factors, a common function is their
involvement in early developmental decisions of cell fates during
embryogenesis [3].
FORKHEAD is a 3-element fingerprint the provides a signature for the fork
head DNA-binding domain. The fingerprint was derived from an initial
alignment of 8 sequences: the motifs were drawn from highly-conserved parts
of the domain, motifs 1 and 3 including the regions encoded by PROSITE
patterns FORK_HEAD_1 (PS00657) and FORK_HEAD_2 (PS00658), which contain a
conserved hexapeptide and heptapeptide in its N-terminal and central
sections. Two iterations on OWL25.1 were required to reach convergence,
at which point a true set comprising 56 sequences was identified.
An update on SPTR37_9f identified a true set of 126 sequences, and 3
partial matches.
|