Abstract
A cell-free system developed from human [oral carcinoma] KB cells was used to transcribe 5.5S RNA from deproteinized adenovirus DNA in vitro. The cell-free RNA synthesis is dependent upon exogenous templates, ribonucleoside triphosphates and cell-free postmitochondrial supernatant of human KB cells. The synthesis of 5.5S RNA is inhibited only by high levels of .alpha.-amanitin; therefore it is carried out by RNA polymerase III. The rate of synthesis was linear for at least 2 h, indicating reinitiation. The 5.5S RNA synthesized in vitro is similar to the corresponding in vito RNA in size, sequence and coding region on adenovirus type 2 DNA. In this report is demonstrated in vitro synthesis of a facsimile of an in vivo transcript directed by deproteinized DNA in a mammalian cell-free postmitochondrial supernatant system.