Sequence of 51 nucleotides at the 3′-end of R17 bacteriophage RNA

Abstract

Three 3′-terminal fragments of R17 RNA have been isolated by polyacrylamide gel electrophoresis from partial T1 ribonuclease and ribonuclease IV digests. The complete nucleotide sequence of the fragments, the largest of which is 51 residues long, have been established by radiochemical methods. A tightly hydrogen-bonded loop probably occurs close to the 3′-terminus of R17 RNA. Within this loop there is a limited region of homology with a 3′-terminal loop in Qβ RNA. The 3′-terminal sequence of R17 RNA contains three potential termination codons, two UAG's and one UAA, no two of which are adjacent. There probably is a region of at least 25 nucleotides at the 3′-end which is not translated into ..