Electron Microscope Study of Length and Partial Denaturation of Rhizobium Bacteriophage DNA

Abstract

By electron microscopy and melting of the DNA of some bacteriophages from the soil bacterium Rhizobium lupini , it was found that molecular weights range between 27 and 50 Mdaltons and GC contents between 53 and 62%. All DNAs studied are linear; one has exposed single-stranded terminals. Partial heat denaturation of two phage DNA permitted mapping of AT-rich sites within unique nucleotide sequences. The maps are asymmetric with respect to the midpoints of the DNA.