Isolation of Escherichia coli transfer RNA-gene hybrids

Abstract

Escherichia coli transfer RNA-DNA hybrids have been isolated from a hybridization complex prepared by hybridization of homologous transfer RNA and DNA in solution. The RNA-DNA hybrid was released from reannealed and unhybridized DNA by Neurospora crassa endonuclease and purified by methylated albumin kieselguhr chromatography, cesium sulfate density-gradient centrifugation and Sephadex G100 chromatography. The purified transfer RNA-gene hybrid had a molecular weight of 50,000 to 60,000, estimated by gel filtration, a density in cesium sulfate of 1.500 g/cm 3, a T m of 81 °C in 0.3 m-saline and a ratio of DNA to RNA of 1.0.