Crystal structure of SULT1A1 bound with PAP

Experimental Data Snapshot

  • Resolution: 2.56 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.216 

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This is version 1.3 of the entry. See complete history


The gate that governs sulfotransferase selectivity.

Cook, I.Wang, T.Almo, S.C.Kim, J.Falany, C.N.Leyh, T.S.

(2013) Biochemistry 52: 415-424

  • DOI: https://doi.org/10.1021/bi301492j
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Human cytosolic sulfotransferases (SULTs) transfer the sulfuryl moiety (-SO(3)) from activated sulfate [3'-phosphoadenosine 5'-phosphosulfate (PAPS)] to the hydroxyls and primary amines of numerous metabolites, drugs, and xenobiotics. Receipt of the sulfuryl group often radically alters acceptor-target interactions. How these enzymes select particular substrates from the hundreds of candidates in a complex cytosol remains an important question. Recent work reveals PAPS binding causes SULT2A1 to undergo an isomerization that controls selectivity by constricting the opening through which acceptors must pass to enter the active site. The enzyme maintains an affinity for large substrates by isomerizing between the open and closed states with nucleotide bound. Here, the molecular basis of the nucleotide-induced closure is explored in equilibrium and nonequilibrium molecular dynamics simulations. The simulations predict that the active-site "cap," which covers both the nucleotide and acceptor binding sites, opens and closes in response to nucleotide. The cap subdivides into nucleotide and acceptor halves whose motions, while coupled, exhibit an independence that can explain the isomerization. In silico weakening of electrostatic interactions between the cap and base of the active site causes the acceptor half of the cap to open and close while the nucleotide lid remains shut. Simulations predict that SULT1A1, the most abundant SULT in human liver, will utilize a similar selection mechanism. This prediction is tested using fulvestrant, an anti-estrogen too large to pass through the closed pore, and estradiol, which is not restricted by closure. Equilibrium and pre-steady-state binding studies confirm that SULT1A1 undergoes a nucleotide-induced isomerzation that controls substrate selection.

  • Organizational Affiliation

    Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461-1926, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Sulfotransferase 1A1
A, B
299Homo sapiensMutation(s): 1 
Gene Names: SULT1A1STPSTP1OK/SW-cl.88
UniProt & NIH Common Fund Data Resources
Find proteins for P50225 (Homo sapiens)
Explore P50225 
Go to UniProtKB:  P50225
PHAROS:  P50225
GTEx:  ENSG00000196502 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP50225
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on A3P

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
C10 H15 N5 O10 P2
Experimental Data & Validation

Experimental Data

  • Resolution: 2.56 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.216 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 48.296α = 90
b = 122.428β = 92.12
c = 55.021γ = 90
Software Package:
Software NamePurpose
CBASSdata collection
HKL-3000data reduction
HKL-3000data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-01-16
    Type: Initial release
  • Version 1.1: 2013-01-23
    Changes: Database references
  • Version 1.2: 2013-02-13
    Changes: Database references
  • Version 1.3: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description