title: tRNA-like elements in Haloferax volcanii.
abstract: All functional RNAs are generated from precursor molecules by a plethora of processing steps. The generation of mature RNA molecules by processing is an important layer of gene expression regulation catalysed by ribonucleases. Here, we analysed 5S rRNA processing in the halophilic Archaeon Haloferax volcanii. Earlier experiments showed that the 5S rRNA is cleaved at its 5' end by the endonuclease tRNase Z. Interestingly, a tRNA-like structure was identified upstream of the 5S rRNA that might be used as a processing signal. Here, we show that this tRNA-like element is indeed recognised as a processing signal by tRNase Z. Substrates containing mutations in the tRNA-like sequence are no longer processed, whereas a substrate containing a deletion in the 5S rRNA sequence is still cleaved. Therefore, an intact 5S rRNA structure is not required for processing. Further, we used bioinformatics analyses to identify additional sequences in Haloferax containing tRNA-like structures. This search resulted in the identification of all tRNAs, the tRNA-like structure upstream of the 5S RNA and 47 new tRNA-like structural elements. However, the in vitro processing of selected examples showed no cleavage of these newly identified elements. Thus, tRNA-like elements are not a general processing signal in Haloferax.
authors.affiliation: Biology II, Ulm University, Albert-Einstein-Allee 11, 89069 Ulm, Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Hölzle
authors.forename: Britta
authors.initials: B
authors.lastname: Stoll
authors.forename: Thomas
authors.initials: T
authors.lastname: Schnattinger
authors.forename: Uwe
authors.initials: U
authors.lastname: Schöning
authors.forename: Brian
authors.initials: B
authors.lastname: Tjaden
authors.forename: Anita
authors.initials: A
authors.lastname: Marchfelder
mesh_terms: D020121:5' Untranslated Regions; D019843:Archaeal Proteins / Q000378:metabolism; D001483:Base Sequence; D004722:Endoribonucleases / Q000378:metabolism; D019622:Haloferax volcanii / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D017354:Point Mutation; D012323:RNA Processing, Post-Transcriptional; D019642:RNA, Archaeal / Q000235:genetics / Q000378:metabolism*; D012341:RNA, Ribosomal, 5S / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion
chemical_list: D020121:5' Untranslated Regions; D019843:Archaeal Proteins; D019642:RNA, Archaeal; D012341:RNA, Ribosomal, 5S; D004722:Endoribonucleases