Testing the sulfotransferase molecular pore hypothesis

Ian T. Cook, Ting Wang, Steven C. Almo, Jungwook Kim, Charles N. Falany, Thomas S. Leyh

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Human cytosolic sulfotransferases (SULTs) regulate the activities of hundreds of signaling metabolites via transfer of the sulfuryl moiety (-SO 3) from activated sulfate (3'-phosphoadenosine 5'-phosphosulfate) to the hydroxyls and primary amines of xeno- and endobiotics. How SULTs select substrates from the scores of competing ligands present in a cytosolic milieu is an important issue in the field. Selectivity appears to be sterically controlled by a molecular pore that opens and closes in response to nucleotide binding. This point of view is fostered by structures showing nucleotide-dependent pore closure and the fact that nucleotide binding induces an isomerization that restricts access to the acceptor-binding pocket. Molecular dynamics models underscore the importance of pore isomerization in selectivity and predict that specific molecular linkages stabilize the closed pore in response to nucleotide binding. To test the pore model, these linkages were disrupted in SULT2A1 via mutagenesis, and the effects on selectivity were determined. The mutations uncoupled nucleotide binding from selectivity and produced enzymes that no longer discriminated between large and small substrates. The mutations did not affect the affinity or turnover of small substrates but resulted in a 183-fold gain in catalytic efficiently toward large substrates. Models predict that an 11-residue "flap" covering the acceptor-binding pocket can open and admit large substrates when nucleotide is bound; a mutant structure demonstrated that this is so. In summary, the model was shown to be a robust, accurate predictor of SULT structure and selectivity whose general features will likely apply to other members of the SULT family.

Original languageEnglish (US)
Pages (from-to)8619-8626
Number of pages8
JournalJournal of Biological Chemistry
Volume288
Issue number12
DOIs
StatePublished - Mar 22 2013

Fingerprint

Sulfotransferases
Nucleotides
Testing
Substrates
Isomerization
Phosphoadenosine Phosphosulfate
Mutagenesis
Mutation
Molecular Models
Xenobiotics
Molecular Dynamics Simulation
Metabolites
Hydroxyl Radical
Sulfates
Amines
Molecular dynamics
Dynamic models
Ligands
Enzymes

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology

Cite this

Testing the sulfotransferase molecular pore hypothesis. / Cook, Ian T.; Wang, Ting; Almo, Steven C.; Kim, Jungwook; Falany, Charles N.; Leyh, Thomas S.

In: Journal of Biological Chemistry, Vol. 288, No. 12, 22.03.2013, p. 8619-8626.

Research output: Contribution to journalArticle

@article{bb82786724d84e0d8e02b8ae947c7e88,
title = "Testing the sulfotransferase molecular pore hypothesis",
abstract = "Human cytosolic sulfotransferases (SULTs) regulate the activities of hundreds of signaling metabolites via transfer of the sulfuryl moiety (-SO 3) from activated sulfate (3'-phosphoadenosine 5'-phosphosulfate) to the hydroxyls and primary amines of xeno- and endobiotics. How SULTs select substrates from the scores of competing ligands present in a cytosolic milieu is an important issue in the field. Selectivity appears to be sterically controlled by a molecular pore that opens and closes in response to nucleotide binding. This point of view is fostered by structures showing nucleotide-dependent pore closure and the fact that nucleotide binding induces an isomerization that restricts access to the acceptor-binding pocket. Molecular dynamics models underscore the importance of pore isomerization in selectivity and predict that specific molecular linkages stabilize the closed pore in response to nucleotide binding. To test the pore model, these linkages were disrupted in SULT2A1 via mutagenesis, and the effects on selectivity were determined. The mutations uncoupled nucleotide binding from selectivity and produced enzymes that no longer discriminated between large and small substrates. The mutations did not affect the affinity or turnover of small substrates but resulted in a 183-fold gain in catalytic efficiently toward large substrates. Models predict that an 11-residue {"}flap{"} covering the acceptor-binding pocket can open and admit large substrates when nucleotide is bound; a mutant structure demonstrated that this is so. In summary, the model was shown to be a robust, accurate predictor of SULT structure and selectivity whose general features will likely apply to other members of the SULT family.",
author = "Cook, {Ian T.} and Ting Wang and Almo, {Steven C.} and Jungwook Kim and Falany, {Charles N.} and Leyh, {Thomas S.}",
year = "2013",
month = "3",
day = "22",
doi = "10.1074/jbc.M112.445015",
language = "English (US)",
volume = "288",
pages = "8619--8626",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "12",

}

TY - JOUR

T1 - Testing the sulfotransferase molecular pore hypothesis

AU - Cook, Ian T.

AU - Wang, Ting

AU - Almo, Steven C.

AU - Kim, Jungwook

AU - Falany, Charles N.

AU - Leyh, Thomas S.

PY - 2013/3/22

Y1 - 2013/3/22

N2 - Human cytosolic sulfotransferases (SULTs) regulate the activities of hundreds of signaling metabolites via transfer of the sulfuryl moiety (-SO 3) from activated sulfate (3'-phosphoadenosine 5'-phosphosulfate) to the hydroxyls and primary amines of xeno- and endobiotics. How SULTs select substrates from the scores of competing ligands present in a cytosolic milieu is an important issue in the field. Selectivity appears to be sterically controlled by a molecular pore that opens and closes in response to nucleotide binding. This point of view is fostered by structures showing nucleotide-dependent pore closure and the fact that nucleotide binding induces an isomerization that restricts access to the acceptor-binding pocket. Molecular dynamics models underscore the importance of pore isomerization in selectivity and predict that specific molecular linkages stabilize the closed pore in response to nucleotide binding. To test the pore model, these linkages were disrupted in SULT2A1 via mutagenesis, and the effects on selectivity were determined. The mutations uncoupled nucleotide binding from selectivity and produced enzymes that no longer discriminated between large and small substrates. The mutations did not affect the affinity or turnover of small substrates but resulted in a 183-fold gain in catalytic efficiently toward large substrates. Models predict that an 11-residue "flap" covering the acceptor-binding pocket can open and admit large substrates when nucleotide is bound; a mutant structure demonstrated that this is so. In summary, the model was shown to be a robust, accurate predictor of SULT structure and selectivity whose general features will likely apply to other members of the SULT family.

AB - Human cytosolic sulfotransferases (SULTs) regulate the activities of hundreds of signaling metabolites via transfer of the sulfuryl moiety (-SO 3) from activated sulfate (3'-phosphoadenosine 5'-phosphosulfate) to the hydroxyls and primary amines of xeno- and endobiotics. How SULTs select substrates from the scores of competing ligands present in a cytosolic milieu is an important issue in the field. Selectivity appears to be sterically controlled by a molecular pore that opens and closes in response to nucleotide binding. This point of view is fostered by structures showing nucleotide-dependent pore closure and the fact that nucleotide binding induces an isomerization that restricts access to the acceptor-binding pocket. Molecular dynamics models underscore the importance of pore isomerization in selectivity and predict that specific molecular linkages stabilize the closed pore in response to nucleotide binding. To test the pore model, these linkages were disrupted in SULT2A1 via mutagenesis, and the effects on selectivity were determined. The mutations uncoupled nucleotide binding from selectivity and produced enzymes that no longer discriminated between large and small substrates. The mutations did not affect the affinity or turnover of small substrates but resulted in a 183-fold gain in catalytic efficiently toward large substrates. Models predict that an 11-residue "flap" covering the acceptor-binding pocket can open and admit large substrates when nucleotide is bound; a mutant structure demonstrated that this is so. In summary, the model was shown to be a robust, accurate predictor of SULT structure and selectivity whose general features will likely apply to other members of the SULT family.

UR - http://www.scopus.com/inward/record.url?scp=84875439090&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84875439090&partnerID=8YFLogxK

U2 - 10.1074/jbc.M112.445015

DO - 10.1074/jbc.M112.445015

M3 - Article

VL - 288

SP - 8619

EP - 8626

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 12

ER -