Halobacterium volcanii tRNAs. Identification of 41 tRNAs covering all amino acids, and the sequences of 33 class I tRNAs.

Transfer RNAs of Halobacterium volcanii, an archaebacterium, were separated by two-dimensional gel electrophoresis and sequenced by a combination of methods. A total of 41 tRNAs, at least one for each amino acid, were identified. These are five tRNAs for Leu, four for Gly, three each for Ala, Arg, Pro, and Ser, two each for Glu, Ile, Lys, Met (initiator and noninitiator), Thr, and Val, and one each for the remaining eight amino acids. As in eucaryotes, only Leu and Ser tRNAs are class II (large extra arm). The sequences of the 33 class I tRNAs, for the remaining 18 amino acids, are presented here. These cover at least 44 codons out of a possible 49 codons for the 18 amino acids. Although these archaebacterial tRNAs follow general tRNA patterns, they are in detail distinct from both eucaryotic and eubacterial tRNAs. Moreover, the initiator tRNA is unique in having a 5'-triphosphorylated end.