TY - JOUR
T1 - A novel three-unit tRNA splicing endonuclease found in ultrasmall Archaea possesses broad substrate specificity
AU - Fujishima, Kosuke
AU - Sugahara, Junichi
AU - Miller, Christopher S.
AU - Baker, Brett J.
AU - Di Giulio, Massimo
AU - Takesue, Kanako
AU - Sato, Asako
AU - Tomita, Masaru
AU - Banfield, Jillian F.
AU - Kanai, Akio
N1 - Funding Information:
Funding for open access charge: Grant-in-Aid for Scientific Research (B) #22370066 from the Ministry of Education, Culture, Sports, Science and Technology of Japan (in part); a research fund at the Institute for Fermentation, Osaka, Japan; research funds at the Yamagata Prefectural Government and Tsuruoka City in Japan; the US Department of Energy, Office of Biological and Environmental Research (DE-SC0004665).
PY - 2011/12
Y1 - 2011/12
N2 - tRNA splicing endonucleases, essential enzymes found in Archaea and Eukaryotes, are involved in the processing of pre-tRNA molecules. In Archaea, three types of splicing endonuclease [homotetrameric: α4, homodimeric: α2, and heterotetrameric: (αβ)2] have been identified, each representing different substrate specificity during the tRNA intron cleavage. Here, we discovered a fourth type of archaeal tRNA splicing endonuclease (2) in the genome of the acidophilic archaeon Candidatus Micrarchaeum acidiphilum, referred to as ARMAN-2 and its closely related species, ARMAN-1. The enzyme consists of two duplicated catalytic units and one structural unit encoded on a single gene, representing a novel three-unit architecture. Homodimeric formation was confirmed by cross-linking assay, and site-directed mutagenesis determined that the conserved L10-pocket interaction between catalytic and structural unit is necessary for the assembly. A tRNA splicing assay reveal that 2 endonuclease cleaves both canonical and non-canonical bulge-helix-bulge motifs, similar to that of (αβ)2 endonuclease. Unlike other ARMAN and Euryarchaeota, tRNAs found in ARMAN-2 are highly disrupted by introns at various positions, which again resemble the properties of archaeal species with (αβ)2 endonuclease. Thus, the discovery of 2 endonuclease in an archaeon deeply branched within Euryarchaeota represents a new example of the coevolution of tRNA and their processing enzymes.
AB - tRNA splicing endonucleases, essential enzymes found in Archaea and Eukaryotes, are involved in the processing of pre-tRNA molecules. In Archaea, three types of splicing endonuclease [homotetrameric: α4, homodimeric: α2, and heterotetrameric: (αβ)2] have been identified, each representing different substrate specificity during the tRNA intron cleavage. Here, we discovered a fourth type of archaeal tRNA splicing endonuclease (2) in the genome of the acidophilic archaeon Candidatus Micrarchaeum acidiphilum, referred to as ARMAN-2 and its closely related species, ARMAN-1. The enzyme consists of two duplicated catalytic units and one structural unit encoded on a single gene, representing a novel three-unit architecture. Homodimeric formation was confirmed by cross-linking assay, and site-directed mutagenesis determined that the conserved L10-pocket interaction between catalytic and structural unit is necessary for the assembly. A tRNA splicing assay reveal that 2 endonuclease cleaves both canonical and non-canonical bulge-helix-bulge motifs, similar to that of (αβ)2 endonuclease. Unlike other ARMAN and Euryarchaeota, tRNAs found in ARMAN-2 are highly disrupted by introns at various positions, which again resemble the properties of archaeal species with (αβ)2 endonuclease. Thus, the discovery of 2 endonuclease in an archaeon deeply branched within Euryarchaeota represents a new example of the coevolution of tRNA and their processing enzymes.
UR - https://www.scopus.com/pages/publications/83755220048
U2 - 10.1093/nar/gkr692
DO - 10.1093/nar/gkr692
M3 - Article
C2 - 21880595
AN - SCOPUS:83755220048
SN - 0305-1048
VL - 39
SP - 9695
EP - 9704
JO - Nucleic Acids Research
JF - Nucleic Acids Research
IS - 22
ER -