%0 Journal Article %A Gupta, Manju %A Carr, N.G. %T Isolation of Polysomes from Nostoc sp. MAC and Translation of Messenger RNA in a Heterologous Cell-free System %D 1983 %J Microbiology, %V 129 %N 8 %P 2359-2366 %@ 1465-2080 %R https://doi.org/10.1099/00221287-129-8-2359 %I Microbiology Society, %X A method has been established which isolates polysomes from the lysozyme/EDTA-shocked cyanobacterium, Nostoc sp. MAC. In a typical preparation the total recovery of RNA as polysomes was 83%, in which 77% of the polysome fraction was present at sizes > 5-mers and 23% as 2–4-mers. Messenger RNA isolated from such a preparation of polysomes produced a 10-fold stimulation in the incorporation of [35S]methionine into polypeptides by a cell-free system of Escherichia coli. The in vitro-synthesized polypeptides were analysed on an SDS-polyacrylamide gradient gel together with in vivo-labelled proteins of Nostoc sp. MAC: seven polypeptides co-migrated with the in vivo-synthesized products. This is the first report of the expression of cyanobacterial messenger RNA in a heterologous cell-free system from E. coli; the efficiency of the system is discussed. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-129-8-2359