[pycrypto] problem with public key import

[Aljoša Mohorović]

i'm getting "ValueError: RSA key format is not supported" when
importing public key.
public key format is the one that can be generated with "ssh-keygen
-y" and i'm using it without "ssh-rsa" at beginning of string.

could somebody post an example howto import this public key using
RSA.importKey(pub)?
basically, what i need to do to transfer public key i have to what
importKey expects?

Aljosa Mohorovic