PROSITE documentation PDOC50804
SCAN box profile


This domain of around 80 amino acid residues has been called LeR because it is a leucine rich region [1], or SCAN box from the first letter of the names of the four proteins initially found to contain it (SRE-ZBP, CTfin-51, AW-1, Number 18 cDNA) [2]. The SCAN box is essentially found in the N-terminal part of transcription factors containing a zinc finger of the C2H2 type (see <PDOC00028>). These proteins can either activate or repress transcription, although isolated recombinant SCAN boxes do not modulate significantly the transcription [1,2]. In addition to these zinc finger transcription factors, an isolated SCAN box without adjacent zinc finger motifs has been identified in some proteins [3,4].

The SCAN box is enriched in hydrophobic and negatively charged residues with a L-X(6)-L motif at its core. This core is flanked by A, E, L, M, H and C residues that are frequently found in α-helices [2]. Predictions of the secondary structure of the domain suggest the presence of at least three α-helices that are separated from one another by short looped regions bounded by proline residues [5]. It has been shown to be a selective oligomerization domain that mediates homotypic and heterotypic interactions between SCAN box containing proteins [4,5].

The following zinc-finger proteins have been shown to contain a SCAN box:

  • CTfin-51, a mouse protein that has been shown to be a strong transcriptional activator.
  • SRE-ZBP, a human transcription factor that could function as a repressor of c-fos transcription.
  • Zinc finger proteins ZNF24, ZNF165, ZNF174, ZNF191, ZNF192, ZNF193, ZNF202, ZNF215, ZNF232, ZNF263, ZFP-29, ZFP-38, and ZFP-95.

And a number of proteins devoid of C2H2-type zinc-finger domain:

  • PGC-2 (PPAR-γ coactivator 2) [3], a human protein that binds to and increases the transcriptional activity of the nuclear receptor PPAR-γ.
  • SDP1 (SCAN-domain protein 1) [4], a protein that interacts with the SCAN box of the zinc finger protein ZNF202.

The profile we developed spans the complete SCAN box.

Last update:

December 2001 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

SCAN_BOX, PS50804; SCAN box profile  (MATRIX)


1AuthorsPengue G. Calabro V. Bartoli P.C. Pagliuca A. Lania L.
TitleRepression of transcriptional activity at a distance by the evolutionarily conserved KRAB domain present in a subfamily of zinc finger proteins.
SourceNucleic Acids Res. 22:2908-2914(1994).
PubMed ID8065901

2AuthorsWilliams A.J. Khachigian L.M. Shows T. Collins T.
TitleIsolation and characterization of a novel zinc-finger protein with transcription repressor activity.
SourceJ. Biol. Chem. 270:22143-22152(1995).
PubMed ID7673192

3AuthorsCastillo G. Brun R.P. Rosenfield J.K. Hauser S. Park C.W. Troy A.E. Wright M.E. Spiegelman B.M.
TitleAn adipogenic cofactor bound by the differentiation domain of PPARgamma.
SourceEMBO J. 18:3676-3687(1999).
PubMed ID10393183

4AuthorsSchumacher C. Wang H. Honer C. Ding W. Koehn J. Lawrence Q. Coulis C.M. Wang L.L. Ballinger D. Bowen B.R. Wagner S.
TitleThe SCAN domain mediates selective oligomerization.
SourceJ. Biol. Chem. 275:17173-17179(2000).
PubMed ID10747874

5AuthorsWilliams A.J. Blacklow S.C. Collins T.
TitleThe zinc finger-associated SCAN box is a conserved oligomerization domain.
SourceMol. Cell. Biol. 19:8526-8535(1999).
PubMed ID10567577

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