Molecular basis for peptidoglycan recognition by a bactericidal lectin

Rebecca E. Lehotzkya, Carrie L. Partchb, Sohini Mukherjeea, Heather L. Casha, William E. Goldman, Kevin H. Gardner, Lora V. Hooper

Research output: Contribution to journalArticle

82 Citations (Scopus)

Abstract

RegIII proteins are secreted C-type lectins that kill Gram-positive bacteria and play a vital role in antimicrobial protection of the mammalian gut. RegIII proteins bind their bacterial targets via interactions with cell wall peptidoglycan but lack the canonical sequences that support calcium-dependent carbohydrate binding in other C-type lectins. Here, we use NMR spectroscopy to determine the molecular basis for peptidoglycan recognition by HIP/PAP, a human RegIII lectin. We show that HIP/PAP recognizes the peptidoglycan carbohydrate backbone in a calcium-independent manner via a conserved "EPN" motif that is critical for bacterial killing. While EPN sequences govern calcium-dependent carbohydrate recognition in other C-type lectins, the unusual location and calcium-independent functionality of the HIP/PAP EPN motif suggest that this sequence is a versatile functional module that can support both calcium-dependent and calcium-independent carbohydrate binding. Further, we show HIP/PAP binding affinity for carbohydrate ligands depends on carbohydrate chain length, supporting a binding model in which HIP/PAP molecules "bind and jump" along the extended polysaccharide chains of peptidoglycan, reducing dissociation rates and increasing binding affinity. We propose that dynamic recognition of highly clustered carbohydrate epitopes in native peptidoglycan is an essential mechanism governing high-affinity interactions between HIP/PAP and the bacterial cell wall.

Original languageEnglish (US)
Pages (from-to)7722-7727
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume107
Issue number17
DOIs
StatePublished - Apr 27 2010

Fingerprint

Peptidoglycan
Lectins
Carbohydrates
Calcium
C-Type Lectins
Cell Wall
Gram-Positive Bacteria
Protein C
Polysaccharides
Epitopes
Magnetic Resonance Spectroscopy
Ligands

Keywords

  • Antimicrobial protein
  • Bacterial cell wall
  • C-type lectin
  • Intestine
  • Nuclear magnetic resonance

ASJC Scopus subject areas

  • General

Cite this

Molecular basis for peptidoglycan recognition by a bactericidal lectin. / Lehotzkya, Rebecca E.; Partchb, Carrie L.; Mukherjeea, Sohini; Casha, Heather L.; Goldman, William E.; Gardner, Kevin H.; Hooper, Lora V.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 107, No. 17, 27.04.2010, p. 7722-7727.

Research output: Contribution to journalArticle

Lehotzkya, Rebecca E. ; Partchb, Carrie L. ; Mukherjeea, Sohini ; Casha, Heather L. ; Goldman, William E. ; Gardner, Kevin H. ; Hooper, Lora V. / Molecular basis for peptidoglycan recognition by a bactericidal lectin. In: Proceedings of the National Academy of Sciences of the United States of America. 2010 ; Vol. 107, No. 17. pp. 7722-7727.
@article{8a9f15ebd1d746ad853053fcfa1e9ce4,
title = "Molecular basis for peptidoglycan recognition by a bactericidal lectin",
abstract = "RegIII proteins are secreted C-type lectins that kill Gram-positive bacteria and play a vital role in antimicrobial protection of the mammalian gut. RegIII proteins bind their bacterial targets via interactions with cell wall peptidoglycan but lack the canonical sequences that support calcium-dependent carbohydrate binding in other C-type lectins. Here, we use NMR spectroscopy to determine the molecular basis for peptidoglycan recognition by HIP/PAP, a human RegIII lectin. We show that HIP/PAP recognizes the peptidoglycan carbohydrate backbone in a calcium-independent manner via a conserved {"}EPN{"} motif that is critical for bacterial killing. While EPN sequences govern calcium-dependent carbohydrate recognition in other C-type lectins, the unusual location and calcium-independent functionality of the HIP/PAP EPN motif suggest that this sequence is a versatile functional module that can support both calcium-dependent and calcium-independent carbohydrate binding. Further, we show HIP/PAP binding affinity for carbohydrate ligands depends on carbohydrate chain length, supporting a binding model in which HIP/PAP molecules {"}bind and jump{"} along the extended polysaccharide chains of peptidoglycan, reducing dissociation rates and increasing binding affinity. We propose that dynamic recognition of highly clustered carbohydrate epitopes in native peptidoglycan is an essential mechanism governing high-affinity interactions between HIP/PAP and the bacterial cell wall.",
keywords = "Antimicrobial protein, Bacterial cell wall, C-type lectin, Intestine, Nuclear magnetic resonance",
author = "Lehotzkya, {Rebecca E.} and Partchb, {Carrie L.} and Sohini Mukherjeea and Casha, {Heather L.} and Goldman, {William E.} and Gardner, {Kevin H.} and Hooper, {Lora V.}",
year = "2010",
month = "4",
day = "27",
doi = "10.1073/pnas.0909449107",
language = "English (US)",
volume = "107",
pages = "7722--7727",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "17",

}

TY - JOUR

T1 - Molecular basis for peptidoglycan recognition by a bactericidal lectin

AU - Lehotzkya, Rebecca E.

AU - Partchb, Carrie L.

AU - Mukherjeea, Sohini

AU - Casha, Heather L.

AU - Goldman, William E.

AU - Gardner, Kevin H.

AU - Hooper, Lora V.

PY - 2010/4/27

Y1 - 2010/4/27

N2 - RegIII proteins are secreted C-type lectins that kill Gram-positive bacteria and play a vital role in antimicrobial protection of the mammalian gut. RegIII proteins bind their bacterial targets via interactions with cell wall peptidoglycan but lack the canonical sequences that support calcium-dependent carbohydrate binding in other C-type lectins. Here, we use NMR spectroscopy to determine the molecular basis for peptidoglycan recognition by HIP/PAP, a human RegIII lectin. We show that HIP/PAP recognizes the peptidoglycan carbohydrate backbone in a calcium-independent manner via a conserved "EPN" motif that is critical for bacterial killing. While EPN sequences govern calcium-dependent carbohydrate recognition in other C-type lectins, the unusual location and calcium-independent functionality of the HIP/PAP EPN motif suggest that this sequence is a versatile functional module that can support both calcium-dependent and calcium-independent carbohydrate binding. Further, we show HIP/PAP binding affinity for carbohydrate ligands depends on carbohydrate chain length, supporting a binding model in which HIP/PAP molecules "bind and jump" along the extended polysaccharide chains of peptidoglycan, reducing dissociation rates and increasing binding affinity. We propose that dynamic recognition of highly clustered carbohydrate epitopes in native peptidoglycan is an essential mechanism governing high-affinity interactions between HIP/PAP and the bacterial cell wall.

AB - RegIII proteins are secreted C-type lectins that kill Gram-positive bacteria and play a vital role in antimicrobial protection of the mammalian gut. RegIII proteins bind their bacterial targets via interactions with cell wall peptidoglycan but lack the canonical sequences that support calcium-dependent carbohydrate binding in other C-type lectins. Here, we use NMR spectroscopy to determine the molecular basis for peptidoglycan recognition by HIP/PAP, a human RegIII lectin. We show that HIP/PAP recognizes the peptidoglycan carbohydrate backbone in a calcium-independent manner via a conserved "EPN" motif that is critical for bacterial killing. While EPN sequences govern calcium-dependent carbohydrate recognition in other C-type lectins, the unusual location and calcium-independent functionality of the HIP/PAP EPN motif suggest that this sequence is a versatile functional module that can support both calcium-dependent and calcium-independent carbohydrate binding. Further, we show HIP/PAP binding affinity for carbohydrate ligands depends on carbohydrate chain length, supporting a binding model in which HIP/PAP molecules "bind and jump" along the extended polysaccharide chains of peptidoglycan, reducing dissociation rates and increasing binding affinity. We propose that dynamic recognition of highly clustered carbohydrate epitopes in native peptidoglycan is an essential mechanism governing high-affinity interactions between HIP/PAP and the bacterial cell wall.

KW - Antimicrobial protein

KW - Bacterial cell wall

KW - C-type lectin

KW - Intestine

KW - Nuclear magnetic resonance

UR - http://www.scopus.com/inward/record.url?scp=77952359819&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77952359819&partnerID=8YFLogxK

U2 - 10.1073/pnas.0909449107

DO - 10.1073/pnas.0909449107

M3 - Article

C2 - 20382864

AN - SCOPUS:77952359819

VL - 107

SP - 7722

EP - 7727

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 17

ER -