Crystal structure of Ancestral variant b9 of SULT 1A1 in complex with PAP and p-nitrophenol

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.210 

wwPDB Validation   3D Report Full Report

Ligand Structure Quality Assessment 

This is version 1.1 of the entry. See complete history


Directed evolution of sulfotransferases and paraoxonases by ancestral libraries.

Alcolombri, U.Elias, M.Tawfik, D.S.

(2011) J Mol Biol 411: 837-853

  • DOI: https://doi.org/10.1016/j.jmb.2011.06.037
  • Primary Citation of Related Structures:  
    3QVU, 3QVV

  • PubMed Abstract: 

    Large libraries of randomly mutated genes are applied in directed evolution experiments in order to obtain sufficient variability. These libraries, however, contain mostly inactive variants, and the very low frequency of improved variants can only be isolated by high-throughput screening. Small but efficient libraries comprise an attractive alternative. Here, we describe the application of ancestral libraries-libraries based on mutations predicted by phylogenetic analysis and ancestral inference. We designed and constructed such libraries using serum paraoxonases and cytosolic sulfotransferases (SULTs) as model enzymes. Both of these enzyme families exhibit a range of activities in drug metabolism and detoxification of xenobiotics. The ancestral serum paraoxonase and SULT libraries were screened by low-throughput means, including HPLC, using substrates and/or reactions with which all family members exhibit low activity. The libraries showed a remarkably high frequency of highly polymorphic and functionally diverse variants. Screening of as few as 300 variants enabled the isolation of mutants with up to 50-fold higher activity than the starting point enzyme. Structural and kinetic characterizations of an evolved SULT variant show how few ancestral mutations reshaped the active site and modulated the enzyme's specificity. Ancestral libraries therefore comprise a means of focusing diversity to positions and mutations that readily trigger changes in substrate and/or reaction specificity, thereby facilitating the isolation of new enzyme variants for a variety of different substrates and reactions by medium-throughput or even low-throughput screens.

  • Organizational Affiliation

    Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Sulfotransferase 1A1
A, B
295Homo sapiensMutation(s): 8 
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
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.210 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 66.86α = 90
b = 71.54β = 90
c = 122.77γ = 90
Software Package:
Software NamePurpose
StructureStudiodata collection
XDSdata reduction
XDSdata scaling

Structure Validation

View Full Validation Report

Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-08-31
    Type: Initial release
  • Version 1.1: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description