Prokaryotic HU and eukaryotic HMG1: a kinked relationship

Abstract

HU and IHF proteins have long been considered the prokaryotic analogues of eukaryotic histones. Their ability to bend DNA, however, is distinctly similar to that of eukaryotic HMG-box proteins, a recently identified family of chromatin components and transcription factors. In some conditions, HU and HMG1-like proteins can even be swapped, both in vitro and in vivo. In spite of this, HU/IHF and HMG-box proteins are not evolutionarily related, and represent two independent solutions for the same biochemical problem.