Transcription termination in the plasmid/virus hybrid pSSVx from Sulfolobus islandicus.
The pSSVx from Sulfolobus islandicus, strain REY15/4, is a hybrid between a plasmid and a fusellovirus. A systematic study previously performed revealed the presence of nine major transcripts, the expression of which was differentially and temporally regulated over the growth cycle of S. islandicus. In this study, two new transcripts were identified. Then, 3' termini of all the RNAs were mapped using adaptor RT-PCR and RNase protection assays, and termination/arrest positions were identified for each transcript. The majority of the identified ending positions were located in the close vicinity of a T-rich sequence and this was consistent with termination signals identifiable for most of archaeal genes. Furthermore, termination also occurred at locations where a T-track sequence was absent but a stem-loop structure could be formed. We propose that an alternative mechanism based on secondary RNA structures and counter-transcripts might be responsible for the transcription termination at these T-track-minus loci in the closely spaced pSSVx genes.
Contursi
Patrizia
P
Archaeal Genetics Laboratory, Department of Molecular Biology, University of Copenhagen, Copenhagen Biocenter Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark. contursi@unina.it
Cannio
Raffaele
R
She
Qunxin
Q
D020413:3' Untranslated Regions; D001483:Base Sequence; D019241:Fuselloviridae / Q000235:genetics*; D015967:Gene Expression Regulation, Viral; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000096:biosynthesis* / Q000737:chemistry; D012367:RNA, Viral / Q000096:biosynthesis* / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D006163:Ribonuclease T1 / Q000378:metabolism; D012259:Ribonuclease, Pancreatic / Q000378:metabolism; D013941:Thymine; D014158:Transcription, Genetic
D020413:3' Untranslated Regions; D012367:RNA, Viral; D006163:Ribonuclease T1; D012259:Ribonuclease, Pancreatic; D013941:Thymine