37SO | pdb_000037so

tC19Z RNA polymerase ribozyme, apo state

• PDB DOI: https://doi.org/10.2210/pdb37SO/pdb
• EM Map EMD-78467: EMDB EMDataResource

• Classification: RNA
• Organism(s): synthetic construct
• Expression System: Escherichia phage T7
• Mutation(s): No 


• Deposited: 2026-08-04 Released: 2026-08-19 
• Deposition Author(s): Hingey, J., Spellmon, N., Yu, Z., Toor, N., Rudolfs, B., Mancino, A., Haack, D.B., Das, R.
• Funding Organization(s): Howard Hughes Medical Institute (HHMI), National Science Foundation (NSF, United States), National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.10 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Predictive improvement of an RNA polymerase ribozyme from its substrate-free cryo-EM structure

Szokoli, D., Hingey, J., Zhiheng, Y., Wu, V., Toor, N., Spellmon, N., Rudolfs, B., Mencino, A., Haack, D.B., Das, R.

To be published.

Biological Assembly 1  

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 195.06 kDa 
• Atom Count: 3,555 
• Modeled Residue Count: 165 
• Deposited Residue Count: 602 
• Unique nucleic acid chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Length	Organism	Image
tC19Z RNA polymerase ribozyme	A	602	synthetic construct

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
MG	B [auth A], C [auth A], D [auth A], E [auth A], F [auth A]	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.10 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.19.2_4158
RECONSTRUCTION	cryoSPARC

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-08-19 
Deposition Author(s): Hingey, J., Spellmon, N., Yu, Z., Toor, N., Rudolfs, B., Mancino, A., Haack, D.B., Das, R.

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Funding Organization	Location	Grant Number
Howard Hughes Medical Institute (HHMI)	United States	--
National Science Foundation (NSF, United States)	United States	2330652
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	R35GM122579
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	R35GM141706

Revision History  

• Version 1.0: 2026-08-19
  Type: Initial release