A coupled transcription-translation system from Agrobacterium tumefaciens and its application to study Ti plasmid expression in vitro.

A coupled transcription-translation system was isolated from A. tumefaciens. Expression of plasmids pBR322 and pKT212 from E.coli, cloned fragments of Ti plasmid (plasmids pSS155 and pSS156) and Ti plasmid derivatives pAL2802, pAL2811, pAL2821 and pAL2832 was analysed in an A. tumefaciens cell-free system and compared with their expression in an E.coli cell-free system. New proteins of 41K and 44K appeared in A tumefaciens extracts, as the result of Ti plasmid expression. These proteins were not found in E.coli extracts.