scan box (LeR)

Introduction

A domain of around 80 amino acid residues has been called LeR because it is a leucine rich region, or SCAN box from the 1st letter of the names of the 4 proteins initially found to contain it. (SRE-ZBP, CTfin-51, AW-1, Number 18 cDNA).

It is a selective oligomerization domain that mediates homotypic & heterotypic interactions between SCAN box containing proteins.

The SCAN box is found in the N-terminal region of transcription factors containing a C2H2 type zinc finger. These proteins can either activate or repress transcription, although isolated recombinant SCAN boxes do not modulate transcription.

In addition to these zinc finger transcription factors, isolated SCAN boxes without adjacent zinc finger motifs have been found in some proteins.

The SCAN box is enriched in hydrophobic & negatively charged residues with a L-X(6)-L motif at its core. This core is flanked by A, E, L, M, H & C residues frequently found in alpha-helices. Predictions of secondary structure suggest at least 3 alpha- helices by short looped regions bounded by Pro.

More general terms

• leucine-rich region