of the Max - MDC

a
b
Figure 1. Conserved DNA binding by cold shock domains. (a) CSD sequence conservation mapped onto the surface of Bc-Csp bound to dT 6 .
Most DNA binding residues are conserved at the level of at least 75% sequence identity (dark green) and similarity (light green). Invariant
surface regions which originate from the protein backbone are colored light blue. (b) Sequence alignment of bacterial cold shock proteins
(top) and Y-box proteins (bottom). Residues which are conserved at the level of at least 75% sequence identity or similarity are highlighted
in black or gray, respectively. Sidechains involved in DNA binding in the Bc-Csp:T 6 crystal structure are marked with triangles. From Max et
al., 2007.
proteins GADD45α and GADD45β, GADD45γ is primarily
localized in the nucleus and displays general antiproliferative
activity. It is distinct, however, with respect to its
expression pattern and cellular activation mechanism. The
recently determined crystal structure of GADD45γ reveals an
α/β-plait topology and shows that the protein forms a
homodimer. In spite of low sequence similarity, the structure
shows striking resemblance to proteins of the large
ribosomal subunit. Archaeal L7ae yields the closest structural
match among proteins represented in the Protein Data
Base. GADD45γ contains an LXXLL motif as present in proteins
that bind to nuclear receptors. The functional significance
of this motif, which is not easily accessible at the protein
surface, and of the structural similarity to ribosomal
proteins awaits further clarification.
110 Cancer Research