Endoribonuclease XendoU

XendoU

the structure of xendou: a splicing independent snorna processing endoribonuclease
Identifiers
Symbol XendoU
Pfam PF09412
InterPro IPR018998

In molecular biology, Endoribonuclease XendoU refers to a protein domain. This particular entry represents endoribonucleases involved in RNA biosynthesis which has been named XendoU in Xenopus laevis (African clawed frog). This protein domain belongs to a family of evolutionarily related proteins. XendoU is a U-specific metal dependent enzyme that produces products with a 2'-3' cyclic phosphate termini.

Function

The endonuclease, XendoU, is highly involved in the biosynthesis of a specific subclass of Xenopus laevis encoded small nucleolar RNAs (snoRNA) which are a large family of non-coding RNAs with essential roles in ribosome biogenesis. Most snoRNAs are encoded in introns and are released through the splicing reaction. Others, instead, produced by an alternative pathway consisting of endonucleolytic processing of pre-mRNA. XendoU, is the endoribonuclease responsible for this activity.[1]

Studies have shown that XendoU-RNA complex is Manganese(Mn2+)-independent.This infers that RNA binding and processing activities can be functionally separated since ions are essential for cleavage.[2]

Structure

XendoU is a single-domain protein with roughly globular shape. It contains nine alpha helices and three antiparallel beta sheets; the latter are clustered on one side of the protein.[1]

Homology

XendoU has no homology to any known cellular RNase. However, it has sequence similarity with proteins tentatively annotated as serine proteases.[2]

References

  1. 1 2 Renzi F, Caffarelli E, Laneve P, Bozzoni I, Brunori M, Vallone B (2006). "The structure of the endoribonuclease XendoU: From small nucleolar RNA processing to severe acute respiratory syndrome coronavirus replication.". Proc Natl Acad Sci U S A. 103 (33): 12365–70. doi:10.1073/pnas.0602426103. PMC 1567885Freely accessible. PMID 16895992.
  2. 1 2 Gioia U, Laneve P, Dlakic M, Arceci M, Bozzoni I, Caffarelli E (2005). "Functional characterization of XendoU, the endoribonuclease involved in small nucleolar RNA biosynthesis.". J Biol Chem. 280 (19): 18996–9002. doi:10.1074/jbc.M501160200. PMID 15755742.

This article incorporates text from the public domain Pfam and InterPro IPR018998

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