RRC ID 50035
Author Kaneta A, Fujishima K, Morikazu W, Hori H, Hirata A.
Title The RNA-splicing endonuclease from the euryarchaeaon Methanopyrus kandleri is a heterotetramer with constrained substrate specificity.
Journal Nucleic Acids Res
Abstract Four different types (α4, α'2, (αβ)2 and ϵ2) of RNA-splicing endonucleases (EndAs) for RNA processing are known to exist in the Archaea. Only the (αβ)2 and ϵ2 types can cleave non-canonical introns in precursor (pre)-tRNA. Both enzyme types possess an insert associated with a specific loop, allowing broad substrate specificity in the catalytic α units. Here, the hyperthermophilic euryarchaeon Methanopyrus kandleri (MKA) was predicted to harbor an (αβ)2-type EndA lacking the specific loop. To characterize MKA EndA enzymatic activity, we constructed a fusion protein derived from MKA α and β subunits (fMKA EndA). In vitro assessment demonstrated complete removal of the canonical bulge-helix-bulge (BHB) intron structure from MKA pre-tRNAAsn. However, removal of the relaxed BHB structure in MKA pre-tRNAGlu was inefficient compared to crenarchaeal (αβ)2 EndA, and the ability to process the relaxed intron within mini-helix RNA was not detected. fMKA EndA X-ray structure revealed a shape similar to that of other EndA types, with no specific loop. Mapping of EndA types and their specific loops and the tRNA gene diversity among various Archaea suggest that MKA EndA is evolutionarily related to other (αβ)2-type EndAs found in the Thaumarchaeota, Crenarchaeota and Aigarchaeota but uniquely represents constrained substrate specificity.
Volume 46(4)
Pages 1958-1972
Published 2018-2-28
DOI 10.1093/nar/gky003
PII 4807343
PMID 29346615
PMC PMC5829648
MeSH Biocatalysis Crystallography, X-Ray Endoribonucleases / chemistry* Endoribonucleases / metabolism Euryarchaeota / enzymology* Evolution, Molecular Introns Models, Molecular Protein Subunits / chemistry Protein Subunits / metabolism RNA Precursors / metabolism RNA, Transfer / chemistry RNA, Transfer / genetics RNA, Transfer / metabolism* Substrate Specificity
IF 11.502
Times Cited 3
DNA material Genomic DNA of Methanopyrus kandleri JCM 9639T (JGD07495)
General Microbes