hide
Free keywords:
-
Abstract:
THE Src-homologous SH3 domain is a small domain present in a large
number of proteins that are involved in signal transduction, such as the
Src protein tyrosine kinase, or in membrane-cytoskeleton interactions,
but the function of SH3 is still unknown (reviewed in refs 1-3). Here we
report the three-dimensional structure at 1.8 angstrom resolution of the
SH3 domain of the cytoskeletal protein spectrin expressed in Escherichia
coli. The domain is a compact beta-barrel made of five antiparallel
beta-strands. The amino acids that are conserved in the SH3 sequences
are located close to each other on one side of the molecule. This
surface is rich in aromatic and carboxylic amino acids, and is distal to
the region of the molecule where the N and C termini reside and where
SH3 inserts into the alpha-spectrin chain. We suggest that a protein
ligand binds to this conserved surface of SH3.
