Investigation of ribosomal RNAs from liver mitochondria of albino rats

: Study of sedimentation coefficients of rat liver mt-rRNAs labelled in vivo under conditions of selective inhibition by actinomycin D of nuclear RNAs biosynthesis, in hypoosmic system of isolated mitochondria, and of mt-rRNAs isolated from purified 55 ribosomes revealed that mt-rRNAs are represented by 16S and 12S components. Both components are found to be of AU-type. Anomalous behaviour of mtRNA on MAK columns is observed. Some aspects of isolation and identification of mt-rRNAs in higher organisms are discussed.