Structural, bioinformatic, and in vivo analyses of two treponema pallidum Lipoproteins reveal a unique TRAP transporter

Ranjit K. Deka, Chad A Brautigam, Martin Goldberg, Peter Schuck, Diana R Tomchick, Michael V Norgard

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Treponema pallidum, the bacterial agent of syphilis, is predicted to encode one tripartite ATP-independent periplasmic transporter (TRAP-T). TRAP-Ts typically employ a periplasmic substrate-binding protein (SBP) to deliver the cognate ligand to the transmembrane symporter. Herein, we demonstrate that the genes encoding the putative TRAP-T components from T. pallidum, tp0957 (the SBP), and tp0958 (the symporter), are in an operon with an uncharacterized third gene, tp0956. We determined the crystal structure of recombinant Tp0956; the protein is trimeric and perforated by a pore. Part of Tp0956 forms an assembly similar to those of "tetratricopeptide repeat" (TPR) motifs. The crystal structure of recombinant Tp0957 was also determined; like the SBPs of other TRAP-Ts, there are two lobes separated by a cleft. In these other SBPs, the cleft binds a negatively charged ligand. However, the cleft of Tp0957 has a strikingly hydrophobic chemical composition, indicating that its ligand may be substantially different and likely hydrophobic. Analytical ultracentrifugation of the recombinant versions of Tp0956 and Tp0957 established that these proteins associate avidly. This unprecedented interaction was confirmed for the native molecules using in vivo cross-linking experiments. Finally, bioinformatic analyses suggested that this transporter exemplifies a new subfamily of TPATs (TPR-protein-associated TRAP-Ts) that require the action of a TPR-containing accessory protein for the periplasmic transport of a potentially hydrophobic ligand(s).

Original languageEnglish (US)
Pages (from-to)678-696
Number of pages19
JournalJournal of Molecular Biology
Volume416
Issue number5
DOIs
StatePublished - Mar 9 2012

Fingerprint

Treponema pallidum
Computational Biology
Lipoproteins
Ligands
Symporters
Adenosine Triphosphate
Periplasmic Binding Proteins
Ultracentrifugation
Protein Transport
Syphilis
Operon
Recombinant Proteins
Genes
Carrier Proteins
Proteins

Keywords

  • protein interactions
  • syphilis
  • TPR motif
  • TRAP transporter
  • Treponema pallidum

ASJC Scopus subject areas

  • Molecular Biology

Cite this

Structural, bioinformatic, and in vivo analyses of two treponema pallidum Lipoproteins reveal a unique TRAP transporter. / Deka, Ranjit K.; Brautigam, Chad A; Goldberg, Martin; Schuck, Peter; Tomchick, Diana R; Norgard, Michael V.

In: Journal of Molecular Biology, Vol. 416, No. 5, 09.03.2012, p. 678-696.

Research output: Contribution to journalArticle

@article{2fe49ab72e734b95b10718b0f119c57d,
title = "Structural, bioinformatic, and in vivo analyses of two treponema pallidum Lipoproteins reveal a unique TRAP transporter",
abstract = "Treponema pallidum, the bacterial agent of syphilis, is predicted to encode one tripartite ATP-independent periplasmic transporter (TRAP-T). TRAP-Ts typically employ a periplasmic substrate-binding protein (SBP) to deliver the cognate ligand to the transmembrane symporter. Herein, we demonstrate that the genes encoding the putative TRAP-T components from T. pallidum, tp0957 (the SBP), and tp0958 (the symporter), are in an operon with an uncharacterized third gene, tp0956. We determined the crystal structure of recombinant Tp0956; the protein is trimeric and perforated by a pore. Part of Tp0956 forms an assembly similar to those of {"}tetratricopeptide repeat{"} (TPR) motifs. The crystal structure of recombinant Tp0957 was also determined; like the SBPs of other TRAP-Ts, there are two lobes separated by a cleft. In these other SBPs, the cleft binds a negatively charged ligand. However, the cleft of Tp0957 has a strikingly hydrophobic chemical composition, indicating that its ligand may be substantially different and likely hydrophobic. Analytical ultracentrifugation of the recombinant versions of Tp0956 and Tp0957 established that these proteins associate avidly. This unprecedented interaction was confirmed for the native molecules using in vivo cross-linking experiments. Finally, bioinformatic analyses suggested that this transporter exemplifies a new subfamily of TPATs (TPR-protein-associated TRAP-Ts) that require the action of a TPR-containing accessory protein for the periplasmic transport of a potentially hydrophobic ligand(s).",
keywords = "protein interactions, syphilis, TPR motif, TRAP transporter, Treponema pallidum",
author = "Deka, {Ranjit K.} and Brautigam, {Chad A} and Martin Goldberg and Peter Schuck and Tomchick, {Diana R} and Norgard, {Michael V}",
year = "2012",
month = "3",
day = "9",
doi = "10.1016/j.jmb.2012.01.015",
language = "English (US)",
volume = "416",
pages = "678--696",
journal = "Journal of Molecular Biology",
issn = "0022-2836",
publisher = "Academic Press Inc.",
number = "5",

}

TY - JOUR

T1 - Structural, bioinformatic, and in vivo analyses of two treponema pallidum Lipoproteins reveal a unique TRAP transporter

AU - Deka, Ranjit K.

AU - Brautigam, Chad A

AU - Goldberg, Martin

AU - Schuck, Peter

AU - Tomchick, Diana R

AU - Norgard, Michael V

PY - 2012/3/9

Y1 - 2012/3/9

N2 - Treponema pallidum, the bacterial agent of syphilis, is predicted to encode one tripartite ATP-independent periplasmic transporter (TRAP-T). TRAP-Ts typically employ a periplasmic substrate-binding protein (SBP) to deliver the cognate ligand to the transmembrane symporter. Herein, we demonstrate that the genes encoding the putative TRAP-T components from T. pallidum, tp0957 (the SBP), and tp0958 (the symporter), are in an operon with an uncharacterized third gene, tp0956. We determined the crystal structure of recombinant Tp0956; the protein is trimeric and perforated by a pore. Part of Tp0956 forms an assembly similar to those of "tetratricopeptide repeat" (TPR) motifs. The crystal structure of recombinant Tp0957 was also determined; like the SBPs of other TRAP-Ts, there are two lobes separated by a cleft. In these other SBPs, the cleft binds a negatively charged ligand. However, the cleft of Tp0957 has a strikingly hydrophobic chemical composition, indicating that its ligand may be substantially different and likely hydrophobic. Analytical ultracentrifugation of the recombinant versions of Tp0956 and Tp0957 established that these proteins associate avidly. This unprecedented interaction was confirmed for the native molecules using in vivo cross-linking experiments. Finally, bioinformatic analyses suggested that this transporter exemplifies a new subfamily of TPATs (TPR-protein-associated TRAP-Ts) that require the action of a TPR-containing accessory protein for the periplasmic transport of a potentially hydrophobic ligand(s).

AB - Treponema pallidum, the bacterial agent of syphilis, is predicted to encode one tripartite ATP-independent periplasmic transporter (TRAP-T). TRAP-Ts typically employ a periplasmic substrate-binding protein (SBP) to deliver the cognate ligand to the transmembrane symporter. Herein, we demonstrate that the genes encoding the putative TRAP-T components from T. pallidum, tp0957 (the SBP), and tp0958 (the symporter), are in an operon with an uncharacterized third gene, tp0956. We determined the crystal structure of recombinant Tp0956; the protein is trimeric and perforated by a pore. Part of Tp0956 forms an assembly similar to those of "tetratricopeptide repeat" (TPR) motifs. The crystal structure of recombinant Tp0957 was also determined; like the SBPs of other TRAP-Ts, there are two lobes separated by a cleft. In these other SBPs, the cleft binds a negatively charged ligand. However, the cleft of Tp0957 has a strikingly hydrophobic chemical composition, indicating that its ligand may be substantially different and likely hydrophobic. Analytical ultracentrifugation of the recombinant versions of Tp0956 and Tp0957 established that these proteins associate avidly. This unprecedented interaction was confirmed for the native molecules using in vivo cross-linking experiments. Finally, bioinformatic analyses suggested that this transporter exemplifies a new subfamily of TPATs (TPR-protein-associated TRAP-Ts) that require the action of a TPR-containing accessory protein for the periplasmic transport of a potentially hydrophobic ligand(s).

KW - protein interactions

KW - syphilis

KW - TPR motif

KW - TRAP transporter

KW - Treponema pallidum

UR - http://www.scopus.com/inward/record.url?scp=84857598413&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84857598413&partnerID=8YFLogxK

U2 - 10.1016/j.jmb.2012.01.015

DO - 10.1016/j.jmb.2012.01.015

M3 - Article

C2 - 22306465

AN - SCOPUS:84857598413

VL - 416

SP - 678

EP - 696

JO - Journal of Molecular Biology

JF - Journal of Molecular Biology

SN - 0022-2836

IS - 5

ER -