1986 Abst. Amer. Soc. Microbiol., Washington, D.C

Polyadenylated RNA Isolated from the Archaebacterium, Halobacterium halobium.

James W. Brown and John N. Reeve , Molecular, Cellular, and Developmental Biology Program, Dept. of Microbiology, The Ohio state University, Columbus, Ohio 43210

Polyadenylated RNA has been isolated from the halophilic archaebacterium Halobacterium halobium by binding to oligo-(dT)-cellulose. The structure of H. halobium poly(A)+ RNA has been compared with that of poly(A)+ RNA from the methanogenic archaebacterium Methanococcus vannielii (J. Bacteriol. 162:909). Preparations of H. halobium poly(A)+ RNA were shown, by electrophoresis, to contain molecules ranging in length from 900 to 2000 bases; sizes compatible with both monocistronic and polycistronic mRNAs. The amount of poly(A) sequences (900 pg/ug cellular RNA) and relative amount of poly(A)+ RNA (1.6% of total RNA) is much higher in H. halobium than in M. vannielii (65 pg/ug RNA and 0.13% of total RNA). The poly(A) tracts from H. halobium poly(A)+ RNA molecules were isolated by RNase A and -digestion and shown to be 12-40 residues in length, approximately twice the lenoth of poly(A) tracts from M. vannielii poly(A)+ RNA. The kinetics of uridine incorporation-into poly(A)+ RNA in H. halobium suggests that polyadenylation of RNAs occurs approximately 30 min. after their transcription.