I have a protein of which its 3D structure is unknown and it has no obvious
sequence homology with any known protein. Its sequence contains a stretch
of 18 polar and charged amino acids: most are lysines and glutamates. The
net charge of this region is approximately neutral. We know that this protein
is mainly alpha-helical, from secondary structure prediction and from CD
measurements. Does anyone has any suggestions or speculation of the function
of this rather unusual neutral but highly charged region? This region is near
the N-terminus of the protein.