Crystal structures of RNA 3'-terminal phosphate cyclase and its complexes with Mg2+ +ATP, ATP or Mn2+

Nucleic Acids Symp Ser (Oxf). 2008:(52):221-2. doi: 10.1093/nass/nrn112.

Abstract

RNA 3'-terminal phosphate cyclase (Rtc) is an enzyme related to RNA splicing, in which the 3'-terminal hydroxyl group of a truncated RNA is converted to the 2',3'-cyclic phosphate that is required prior to RNA ligation. This reaction may occur in the following two steps: (i) Rtc + ATP --> Rtc-AMP + Ppi and (ii) RNA-N3' + Rtc-AMP --> RNA-N>p + Rtc + AMP. In order to establish the reaction mechanism, Rtc of Sulfolobus tokodaii, overexpressed in E. coli, was crystallized in the following states, Rtc, Rtc-AMP, Rtc:AMP, Rtc:ATP and Rtc:Mn, and their crystal structures have been determined at 2.25, 2.25, 2.9, 2.4 and 3.2 A resolutions, respectively. Based on these structures, a possible reaction mechanism has been proposed.

MeSH terms

  • Adenosine Monophosphate / chemistry
  • Adenosine Triphosphate / chemistry*
  • Crystallography, X-Ray
  • Ligases / chemistry*
  • Magnesium / chemistry*
  • Manganese / chemistry*
  • Models, Molecular
  • Protein Conformation
  • Sulfolobus / enzymology

Substances

  • Adenosine Monophosphate
  • Manganese
  • Adenosine Triphosphate
  • Ligases
  • RNA 3'-terminal phosphate cyclase
  • Magnesium