Molecular insights into the enzymatic diversity of flavin-trafficking protein (Ftp; formerly ApbE) in flavoprotein biogenesis in the bacterial periplasm

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

We recently reported a flavin-trafficking protein (Ftp) in the syphilis spirochete Treponema pallidum (Ftp_Tp) as the first bacterial metal-dependent FAD pyrophosphatase that hydrolyzes FAD into AMP and FMN in the periplasm. Orthologs of Ftp_Tp in other bacteria (formerly ApbE) appear to lack this hydrolytic activity; rather, they flavinylate the redox subunit, NqrC, via their metal-dependent FMN transferase activity. However, nothing has been known about the nature or mechanism of metal-dependent Ftp catalysis in either Nqr- or Rnf-redox-containing bacteria. In the current study, we identified a bimetal center in the crystal structure of Escherichia coli Ftp (Ftp_Ec) and show via mutagenesis that a single amino acid substitution converts it from an FAD-binding protein to a Mg2+-dependent FAD pyrophosphatase (Ftp_Tp-like). Furthermore, in the presence of protein substrates, both types of Ftps are capable of flavinylating periplasmic redox-carrying proteins (e.g., RnfG_Ec) via the metal-dependent covalent attachment of FMN. A high-resolution structure of the Ftp-mediated flavinylated protein of Shewanella oneidensis NqrC identified an essential lysine in phosphoester-threonyl-FMN bond formation in the posttranslationally modified flavoproteins. Together, these discoveries broaden our understanding of the physiological capabilities of the bacterial periplasm, and they also clarify a possible mechanism by which flavoproteins are generated.

Original languageEnglish (US)
Pages (from-to)21-38
Number of pages18
JournalMicrobiologyOpen
Volume5
Issue number1
DOIs
StatePublished - Feb 1 2016

Fingerprint

Flavoproteins
Periplasm
Protein Transport
Flavin Mononucleotide
FAD pyrophosphatase
Metals
Oxidation-Reduction
Flavin-Adenine Dinucleotide
Shewanella
Bacteria
Treponema pallidum
Spirochaetales
Proteins
4,6-dinitro-o-cresol
Amino Acid Substitution
Adenosine Monophosphate
Syphilis
Transferases
Catalysis
Mutagenesis

Keywords

  • FAD pyrophosphatase
  • Flavoprotein
  • FMN transferase
  • Lipoprotein
  • Posttranslational modification
  • Redox protein

ASJC Scopus subject areas

  • Microbiology

Cite this

@article{481112cd33e647d0819bd4ea29ec5831,
title = "Molecular insights into the enzymatic diversity of flavin-trafficking protein (Ftp; formerly ApbE) in flavoprotein biogenesis in the bacterial periplasm",
abstract = "We recently reported a flavin-trafficking protein (Ftp) in the syphilis spirochete Treponema pallidum (Ftp_Tp) as the first bacterial metal-dependent FAD pyrophosphatase that hydrolyzes FAD into AMP and FMN in the periplasm. Orthologs of Ftp_Tp in other bacteria (formerly ApbE) appear to lack this hydrolytic activity; rather, they flavinylate the redox subunit, NqrC, via their metal-dependent FMN transferase activity. However, nothing has been known about the nature or mechanism of metal-dependent Ftp catalysis in either Nqr- or Rnf-redox-containing bacteria. In the current study, we identified a bimetal center in the crystal structure of Escherichia coli Ftp (Ftp_Ec) and show via mutagenesis that a single amino acid substitution converts it from an FAD-binding protein to a Mg2+-dependent FAD pyrophosphatase (Ftp_Tp-like). Furthermore, in the presence of protein substrates, both types of Ftps are capable of flavinylating periplasmic redox-carrying proteins (e.g., RnfG_Ec) via the metal-dependent covalent attachment of FMN. A high-resolution structure of the Ftp-mediated flavinylated protein of Shewanella oneidensis NqrC identified an essential lysine in phosphoester-threonyl-FMN bond formation in the posttranslationally modified flavoproteins. Together, these discoveries broaden our understanding of the physiological capabilities of the bacterial periplasm, and they also clarify a possible mechanism by which flavoproteins are generated.",
keywords = "FAD pyrophosphatase, Flavoprotein, FMN transferase, Lipoprotein, Posttranslational modification, Redox protein",
author = "Deka, {Ranjit K.} and Brautigam, {Chad A} and Liu, {Wei Z.} and Tomchick, {Diana R} and Norgard, {Michael V}",
year = "2016",
month = "2",
day = "1",
doi = "10.1002/mbo3.306",
language = "English (US)",
volume = "5",
pages = "21--38",
journal = "MicrobiologyOpen",
issn = "2045-8827",
publisher = "John Wiley and Sons Inc.",
number = "1",

}

TY - JOUR

T1 - Molecular insights into the enzymatic diversity of flavin-trafficking protein (Ftp; formerly ApbE) in flavoprotein biogenesis in the bacterial periplasm

AU - Deka, Ranjit K.

AU - Brautigam, Chad A

AU - Liu, Wei Z.

AU - Tomchick, Diana R

AU - Norgard, Michael V

PY - 2016/2/1

Y1 - 2016/2/1

N2 - We recently reported a flavin-trafficking protein (Ftp) in the syphilis spirochete Treponema pallidum (Ftp_Tp) as the first bacterial metal-dependent FAD pyrophosphatase that hydrolyzes FAD into AMP and FMN in the periplasm. Orthologs of Ftp_Tp in other bacteria (formerly ApbE) appear to lack this hydrolytic activity; rather, they flavinylate the redox subunit, NqrC, via their metal-dependent FMN transferase activity. However, nothing has been known about the nature or mechanism of metal-dependent Ftp catalysis in either Nqr- or Rnf-redox-containing bacteria. In the current study, we identified a bimetal center in the crystal structure of Escherichia coli Ftp (Ftp_Ec) and show via mutagenesis that a single amino acid substitution converts it from an FAD-binding protein to a Mg2+-dependent FAD pyrophosphatase (Ftp_Tp-like). Furthermore, in the presence of protein substrates, both types of Ftps are capable of flavinylating periplasmic redox-carrying proteins (e.g., RnfG_Ec) via the metal-dependent covalent attachment of FMN. A high-resolution structure of the Ftp-mediated flavinylated protein of Shewanella oneidensis NqrC identified an essential lysine in phosphoester-threonyl-FMN bond formation in the posttranslationally modified flavoproteins. Together, these discoveries broaden our understanding of the physiological capabilities of the bacterial periplasm, and they also clarify a possible mechanism by which flavoproteins are generated.

AB - We recently reported a flavin-trafficking protein (Ftp) in the syphilis spirochete Treponema pallidum (Ftp_Tp) as the first bacterial metal-dependent FAD pyrophosphatase that hydrolyzes FAD into AMP and FMN in the periplasm. Orthologs of Ftp_Tp in other bacteria (formerly ApbE) appear to lack this hydrolytic activity; rather, they flavinylate the redox subunit, NqrC, via their metal-dependent FMN transferase activity. However, nothing has been known about the nature or mechanism of metal-dependent Ftp catalysis in either Nqr- or Rnf-redox-containing bacteria. In the current study, we identified a bimetal center in the crystal structure of Escherichia coli Ftp (Ftp_Ec) and show via mutagenesis that a single amino acid substitution converts it from an FAD-binding protein to a Mg2+-dependent FAD pyrophosphatase (Ftp_Tp-like). Furthermore, in the presence of protein substrates, both types of Ftps are capable of flavinylating periplasmic redox-carrying proteins (e.g., RnfG_Ec) via the metal-dependent covalent attachment of FMN. A high-resolution structure of the Ftp-mediated flavinylated protein of Shewanella oneidensis NqrC identified an essential lysine in phosphoester-threonyl-FMN bond formation in the posttranslationally modified flavoproteins. Together, these discoveries broaden our understanding of the physiological capabilities of the bacterial periplasm, and they also clarify a possible mechanism by which flavoproteins are generated.

KW - FAD pyrophosphatase

KW - Flavoprotein

KW - FMN transferase

KW - Lipoprotein

KW - Posttranslational modification

KW - Redox protein

UR - http://www.scopus.com/inward/record.url?scp=84962269421&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84962269421&partnerID=8YFLogxK

U2 - 10.1002/mbo3.306

DO - 10.1002/mbo3.306

M3 - Article

C2 - 26626129

AN - SCOPUS:84962269421

VL - 5

SP - 21

EP - 38

JO - MicrobiologyOpen

JF - MicrobiologyOpen

SN - 2045-8827

IS - 1

ER -