title: Structure, function, and evolution of the tRNA endonucleases of Archaea: an example of subfunctionalization.
abstract: We have detected two paralogs of the tRNA endonuclease gene of Methanocaldococcus jannaschii in the genome of the crenarchaeote Sulfolobus solfataricus. This finding has led to the discovery of a previously unrecognized oligomeric form of the enzyme. The two genes code for two different subunits, both of which are required for cleavage of the pre-tRNA substrate. Thus, there are now three forms of tRNA endonuclease in the Archaea: a homotetramer in some Euryarchaea, a homodimer in other Euryarchaea, and a heterotetramer in the Crenarchaea and the Nanoarchaea. The last-named enzyme, arising most likely by gene duplication and subsequent "subfunctionalization," requires the products of both genes to be active.
authors.affiliation: Istituto di Biologia Cellulare, Consiglio Nazionale delle Ricerche, Campus A. Buzzati-Traverso, Via Ramarini 32, I-00016 Monterotondo Scalo, Rome, Italy. g.tocchini@ibc.cnr.it
authors.forename: Giuseppe D
authors.initials: GD
authors.lastname: Tocchini-Valentini
authors.forename: Paolo
authors.initials: P
authors.lastname: Fruscoloni
authors.forename: Glauco P
authors.initials: GP
authors.lastname: Tocchini-Valentini
mesh_terms: D001105:Archaea / Q000201:enzymology* / Q000235:genetics; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism; D004722:Endoribonucleases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D008958:Models, Molecular; D011487:Protein Conformation; D019642:RNA, Archaeal / Q000235:genetics / Q000378:metabolism; D012343:RNA, Transfer / Q000235:genetics* / Q000378:metabolism*
chemical_list: D019843:Archaeal Proteins; D019642:RNA, Archaeal; D012343:RNA, Transfer; D004722:Endoribonucleases