Modomics - A Database of RNA Modifications

ID Card:

Full name: RNA triphosphatase Cet1
Synonym: Polynucleotide 5'-triphosphatase, mRNA 5'-triphosphatase, Tpase
GI: 308153424
Orf: P1433
COG: COG4943
UniProt: O13297
Structures: | 1D8H | 1D8I |
Alpha Fold Predicted Structure: AF-O13297-F1
Enzyme type: triphosphatase/hydrolase
Position of modification - modification: m:0 - m7GpppN


PDB Structures:


1D8H

Structure Description:

Title:
Classification:
Technique:

Abstract of the PDB Structure's related Publication:

RNA triphosphatase is an essential mRNA processing enzyme that catalyzes the first step in cap formation. The 2.05 A crystal structure of yeast RNA triphosphatase Cet1p reveals a novel active site fold whereby an eight-stranded beta barrel forms a topologically closed triphosphate tunnel. Interactions of a sulfate in the center of the tunnel with a divalent cation and basic amino acids projecting into the tunnel suggest a catalytic mechanism that is supported by mutational data. Discrete surface domains mediate Cet1p homodimerization and Cet1p binding to the guanylyltransferase component of the capping apparatus. The structure and mechanism of fungal RNA triphosphatases are completely different from those of mammalian mRNA capping enzymes. Hence, RNA triphosphatase presents an ideal target for structure-based antifungal drug discovery.

Download RCSB-PDB Structures:

Pdb Files   1D8H.pdb   1D8I.pdb  
Pdbx/mmCIF Files   1D8H.cif   1D8I.cif  


Protein sequence:

MSYTDNPPQTKRALSLDDLVNHDENEKVKLQKLSEAANGSRPFAENLESDINQTETGQAAPIDNYKESTGHGSHSQKPKSRKSSNDDEETDTDDEMGASGEINFDSEMDFDYDKQHRNLLSNGSPPMNDGSDANAKLEKPSDDSIHQNSKSDEEQRIPKQGNEGNIASNYITQVPLQKQKQTEKKIAGNAVGSVVKKEEEANAAVDNIFEEKATLQSKKNNIKRDLEVLNEISASSKPSKYKNVPIWAQKWKPTIKALQSINVKDLKIDPSFLNIIPDDDLTKSVQDWVYATIYSIAPELRSFIELEMKFGVIIDAKGPDRVNPPVSSQCVFTELDAHLTPNIDASLFKELSKYIRGISEVTENTGKFSIIESQTRDSVYRVGLSTQRPRFLRMSTDIKTGRVGQFIEKRHVAQLLLYSPKDSYDVKISLNLELPVPDNDPPEKYKSQSPISERTKDRVSYIHNDSCTRIDITKVENHNQNSKSRQSETTHEVELEINTPALLNAFDNITNDSKEYASLIRTFLNNGTIIRRKLSSLSYEIFEGSKKVM

Comments:

S.cerevisiae Triphosphatase Cet1 and RNA guanylyltransferase (Ceg1) interact in vivo and in vitro to form a bifunctional mRNA capping enzyme complex (Haussmann et al. 2001 ) . Indeed, an Essential Function of Saccharomyces cerevisiae RNA Triphosphatase Cet1 Is to Stabilize RNA Guanylyltransferase Ceg1 against thermal inactivation. The guanylyltransferase activity of the mRNA capping -enzyme catalyzes the transfer of GMP from GTP to the 5' terminus of mRNA. In S.cerevisiae the activity is carried on the alpha subunit of the capping enzyme, the product of the CEG1 gene (Yamagishi et al. 1995) . 5' guanine - N7 cap is essential for all eukaryotic organisms examined thus far and is the first co-transcriptional modification of cellular pre-messenger RNA. It represses RNA polymerase II transcription in vivo, suggesting a bidirectional flow of information between capping and transcription. TPase. Hydrolyzes the 5'-triphosphate end of nascent pre-mRNA to a 5'-diphosphate. The role of Ceg1-Cet1 interaction is to allostericaly activate Cet1.




Reaction Substrate SubstrateType Position (Anti)Codon Modified (Anti)Codon Amino Acid Change Transcript Name Transcript Region Cellular Localization References
pppN:ppN RNA mRNA 0 5' - END Nucleoplasm 9345280   

Alpha Fold Predicted Structure:






Clear Selection and Reset Camera

Protein sequence:

M S Y T D N P P Q T K R A L S L D D L V N H D E N E K V K L Q K L S E A A N G S R P F A E N L E S D I N Q T E T G Q A A P I D N Y K E S T G H G S H S Q K P K S R K S S N D D E E T D T D D E M G A S G E I N F D S E M D F D Y D K Q H R N L L S N G S P P M N D G S D A N A K L E K P S D D S I H Q N S K S D E E Q R I P K Q G N E G N I A S N Y I T Q V P L Q K Q K Q T E K K I A G N A V G S V V K K E E E A N A A V D N I F E E K A T L Q S K K N N I K R D L E V L N E I S A S S K P S K Y K N V P I W A Q K W K P T I K A L Q S I N V K D L K I D P S F L N I I P D D D L T K S V Q D W V Y A T I Y S I A P E L R S F I E L E M K F G V I I D A K G P D R V N P P V S S Q C V F T E L D A H L T P N I D A S L F K E L S K Y I R G I S E V T E N T G K F S I I E S Q T R D S V Y R V G L S T Q R P R F L R M S T D I K T G R V G Q F I E K R H V A Q L L L Y S P K D S Y D V K I S L N L E L P V P D N D P P E K Y K S Q S P I S E R T K D R V S Y I H N D S C T R I D I T K V E N H N Q N S K S R Q S E T T H E V E L E I N T P A L L N A F D N I T N D S K E Y A S L I R T F L N N G T I I R R K L S S L S Y E I F E G S K K V M

Secondary Structure Alphabet

  • G: 3-turn helix (310helix)
  • H: α-helix
  • I: 𝝅-helix (5 - turn helix)
  • T: Hydrogen Bonded Turn
  • B: β-sheet
  • S: Bend
  • C: Coil (residues not present in any of the above conformations)
  • N: Not assigned

Download PDB Structures & DSSP Secondary Structures:

Alpha Fold Pdb Files   AF-O13297-F1.pdb  
Alpha Fold Pdbx/mmCIF Files   AF-O13297-F1.cif  
DSSP Secondary Structures   O13297.dssp  





Publications:

Title Authors Journal Details PubMed Id DOI
Isolation and characterization of the yeast mRNA capping enzyme beta subunit gene encoding RNA 5'-triphosphatase, which is essential for cell viability. Tsukamoto T, Shibagaki Y, Imajoh-Ohmi S, Murakoshi T, Suzuki M, Nakamura A, Gotoh H, Mizumoto K Biochem Biophys Res Commun [details] 9345280 -
Structure and mechanism of yeast RNA triphosphatase: an essential component of the mRNA capping apparatus. Lima CD, Wang LK, Shuman S Cell [details] 10589681 -
Structure of the Saccharomyces cerevisiae Cet1-Ceg1 mRNA capping apparatus. Gu M, Rajashankar KR, Lima CD Structure [details] 20159466 -
The essential interaction between yeast mRNA capping enzyme subunits is not required for triphosphatase function in vivo. Takase Y, Takagi T, Komarnitsky PB, Buratowski S Mol Cell Biol [details] 11094081 -
An essential function of Saccharomyces cerevisiae RNA triphosphatase Cet1 is to stabilize RNA guanylyltransferase Ceg1 against thermal inactivation. Hausmann S, Ho CK, Schwer B, Shuman S... J Biol Chem [details] 11463793 -

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