STRUCTURE-SPECIFIC DS SS-RNASE ACTIVITY IN THE EXTREME HALOPHILE HALOBACTERIUM-SALINARIUM/

A ds/ss-RNA processing activity involved in antisense-RNA mediated gen e regulation in the extremely halophilic archaebacterium Halobacterium salinarium was investigated in vivo. H.salinarium cells were transfor med with DNA encoding an RNA species complementary to a part of the ma jor lytic transcript, termed T4, of the H.salinarium phage phiH. The t ransformants transcribing this construct, when infected by phage were able to process T4 in a similar way to the processing of the lytic tra nscript denoted T1, in the natural sense-antisense system. Processing of T4 was not observed under normal phage growth on wild-type cells. T hus the antisense-RNA mediated processing activity earlier reported is dependent on the presence of an RNA duplex and is not sequence specif ic.