PROKARYOTIC HU AND EUKARYOTIC HMG1 - A KINKED RELATIONSHIP

HU and IHF proteins have long been considered the prokaryotic analogue s of eukaryotic histones. Their ability to bend DNA, however, is disti nctly similar to that of eukaryotic HMG-box proteins, a recently ident ified family of chromatin components and transcription factors. In som e conditions, HU and HMG1-like proteins can even be swapped, both in v itro and in vivo. In spite of this, HU/IHF and HMG-box proteins are no t evolutionarily related, and represent two independent solutions for the same biochemical problem.