J. Biol. Chem., Vol. 255, Issue 2, 492-497, 01, 1980
An in vitro protein-synthesizing system with isolated chloroplasts of Sorghum vulgare. An alternate assay system for exogenous template RNA
V Geetha and A Gnanam
A light-dependent in vitro protein-synthesizing system from isolated
mesophyll chloroplasts of Sorghum vulgare was characterized. Preincubation
of chloroplasts in light at 25 degrees C for 1 h depleted the endogenous
templates completely; such preincubated chloroplasts translated exogenously
added homologous, heterologous, and synthetic templates efficiently. The
fidelity of the system in translating added templates was tested with
specific templates. Substantive evidence for the fidelity of the system was
obtained by immunological analysis of the specific products, e.g.
chloroplast coupling Factor I obtained by the translation of S. vulgare
leaf cellular and chloroplast RNAs. The efficiency of the system in
translating the exogenous mRNA was also quite high. As the endogenous mRNA
was totally depleted during preincubation, and as the system was
nonspecific for the source of RNA for translation, these chloroplasts can
serve as a simple alternative system for assaying the role of diverse
template RNAs.