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Title: Structural Similarities between Thiamin-Binding Protein and Thiaminase-I Suggest a Common Ancestor

Abstract

ATP-binding cassette (ABC) transporters are responsible for the transport of a wide variety of water-soluble molecules and ions into prokaryotic cells. In Gram-negative bacteria, periplasmic-binding proteins deliver ions or molecules such as thiamin to the membrane-bound ABC transporter. The gene for the thiamin-binding protein tbpA has been identified in both Escherichia coli and Salmonella typhimurium. Here we report the crystal structure of TbpA from E. coli with bound thiamin monophosphate. The structure was determined at 2.25 {angstrom} resolution using single-wavelength anomalous diffraction experiments, despite the presence of nonmerohedral twinning. The crystal structure shows that TbpA belongs to the group II periplasmic-binding protein family. Equilibrium binding measurements showed similar dissociation constants for thiamin, thiamin monophosphate, and thiamin pyrophosphate. Analysis of the binding site by molecular modeling demonstrated how TbpA binds all three forms of thiamin. A comparison of TbpA and thiaminase-I, a thiamin-degrading enzyme, revealed structural similarity between the two proteins, especially in domain 1, suggesting that the two proteins evolved from a common ancestor.

Authors:
; ; ; ; ;  [1]
  1. Cornell
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE
OSTI Identifier:
1006509
Resource Type:
Journal Article
Journal Name:
Biochem. J.
Additional Journal Information:
Journal Volume: 47; Journal Issue: (5) ; 2008; Journal ID: ISSN 0006-2936
Country of Publication:
United States
Language:
ENGLISH
Subject:
36 MATERIALS SCIENCE; BACTERIA; CRYSTAL STRUCTURE; DIFFRACTION; DISSOCIATION; EQUILIBRIUM; ESCHERICHIA COLI; GENES; IONS; MOLECULES; PROTEINS; RESOLUTION; SALMONELLA TYPHIMURIUM; SIMULATION; TRANSPORT; TWINNING

Citation Formats

Soriano, Erika V, Rajashankar, Kanagalaghatta R, Hanes, Jeremiah W, Bale, Shridhar, Begley, Tadhg P, and Ealick, Steven E. Structural Similarities between Thiamin-Binding Protein and Thiaminase-I Suggest a Common Ancestor. United States: N. p., 2008. Web. doi:10.1021/bi7018282.
Soriano, Erika V, Rajashankar, Kanagalaghatta R, Hanes, Jeremiah W, Bale, Shridhar, Begley, Tadhg P, & Ealick, Steven E. Structural Similarities between Thiamin-Binding Protein and Thiaminase-I Suggest a Common Ancestor. United States. https://doi.org/10.1021/bi7018282
Soriano, Erika V, Rajashankar, Kanagalaghatta R, Hanes, Jeremiah W, Bale, Shridhar, Begley, Tadhg P, and Ealick, Steven E. 2008. "Structural Similarities between Thiamin-Binding Protein and Thiaminase-I Suggest a Common Ancestor". United States. https://doi.org/10.1021/bi7018282.
@article{osti_1006509,
title = {Structural Similarities between Thiamin-Binding Protein and Thiaminase-I Suggest a Common Ancestor},
author = {Soriano, Erika V and Rajashankar, Kanagalaghatta R and Hanes, Jeremiah W and Bale, Shridhar and Begley, Tadhg P and Ealick, Steven E},
abstractNote = {ATP-binding cassette (ABC) transporters are responsible for the transport of a wide variety of water-soluble molecules and ions into prokaryotic cells. In Gram-negative bacteria, periplasmic-binding proteins deliver ions or molecules such as thiamin to the membrane-bound ABC transporter. The gene for the thiamin-binding protein tbpA has been identified in both Escherichia coli and Salmonella typhimurium. Here we report the crystal structure of TbpA from E. coli with bound thiamin monophosphate. The structure was determined at 2.25 {angstrom} resolution using single-wavelength anomalous diffraction experiments, despite the presence of nonmerohedral twinning. The crystal structure shows that TbpA belongs to the group II periplasmic-binding protein family. Equilibrium binding measurements showed similar dissociation constants for thiamin, thiamin monophosphate, and thiamin pyrophosphate. Analysis of the binding site by molecular modeling demonstrated how TbpA binds all three forms of thiamin. A comparison of TbpA and thiaminase-I, a thiamin-degrading enzyme, revealed structural similarity between the two proteins, especially in domain 1, suggesting that the two proteins evolved from a common ancestor.},
doi = {10.1021/bi7018282},
url = {https://www.osti.gov/biblio/1006509}, journal = {Biochem. J.},
issn = {0006-2936},
number = (5) ; 2008,
volume = 47,
place = {United States},
year = {Mon Jun 30 00:00:00 EDT 2008},
month = {Mon Jun 30 00:00:00 EDT 2008}
}