title: Crystal structures of RNA 3'-terminal phosphate cyclase and its complexes with Mg2+ +ATP, ATP or Mn2+.
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.
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Shimizu
authors.forename: Masanori
authors.initials: M
authors.lastname: Ohki
authors.forename: Nami
authors.initials: N
authors.lastname: Ohkubo
authors.forename: Kaoru
authors.initials: K
authors.lastname: Suzuki
authors.forename: Masaru
authors.initials: M
authors.lastname: Tsunoda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sekiguchi
authors.forename: Akio
authors.initials: A
authors.lastname: Takénaka
mesh_terms: D000249:Adenosine Monophosphate / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008025:Ligases / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D011487:Protein Conformation; D016944:Sulfolobus / Q000201:enzymology
chemical_list: D000249:Adenosine Monophosphate; D008345:Manganese; D000255:Adenosine Triphosphate; D008025:Ligases; C037451:RNA 3'-terminal phosphate cyclase; D008274:Magnesium