Overproduction and rapid purification of the Escherichia coli histone-like protein, H-NS

E. coli cells produce a set of small and usually basic DNA-binding proteins, which were collectively termed histone-like proteins because their biochemical properties were thought to resemble those of eukaryotic histone.1* Of the five such histone-like proteins so far characterized, H-NS (or HIa) is an abundant and neutral one, with an apparent molecular weight of 16,000. The gene for H-NS has recently been cloned, sequenced, and mapped at 27 min on the E. coli genetic map.2)3) Results of previous extensive genetic studies on H-NS suggested that the product of the hns locus is an important DNA-binding protein for both the function and the architecture of nucleoprotein complexes concerned in crucial biological processes.4) Another intriguing finding on a possible