Kluyveromyces lactis γ-toxin, a ribonuclease that recognizes the anticodon stem loop of tRNA
2008 (English)In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 36, no 4, 1072-1080 p.Article in journal (Refereed) Published
Kluyveromyces lactis gamma-toxin is a tRNA endonuclease that cleaves Saccharomyces cerevisiae [see text] between position 34 and position 35. All three substrate tRNAs carry a 5-methoxycarbonylmethyl-2-thiouridine (mcm(5)s(2)U) residue at position 34 (wobble position) of which the mcm(5) group is required for efficient cleavage. However, the different cleavage efficiencies of mcm(5)s(2)U(34)-containing tRNAs suggest that additional features of these tRNAs affect cleavage. In the present study, we show that a stable anticodon stem and the anticodon loop are the minimal requirements for cleavage by gamma-toxin. A synthetic minihelix RNA corresponding to the anticodon stem loop (ASL) of the natural substrate [see text] is cleaved at the same position as the natural substrate. In [see text], the nucleotides U(34)U(35)C(36)A(37)C(38) are required for optimal gamma-toxin cleavage, whereas a purine at position 32 or a G in position 33 dramatically reduces the cleavage of the ASL. Comparing modified and partially modified forms of E. coli and yeast [see text] reinforced the strong stimulatory effects of the mcm(5) group, revealed a weak positive effect of the s(2) group and a negative effect of the bacterial 5-methylaminomethyl (mnm(5)) group. The data underscore the high specificity of this yeast tRNA toxin.
Place, publisher, year, edition, pages
2008. Vol. 36, no 4, 1072-1080 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:umu:diva-20534DOI: 10.1093/nar/gkm1121PubMedID: 18096622OAI: oai:DiVA.org:umu-20534DiVA: diva2:208858