Abstract
The ability of a pathogenic bacterium to scavenge iron from its host is important for its growth and survival during an infection. Our studies on C. perfringens gas gangrene strain JIR325, a derivative of strain 13, showed that it is capable of utilizing both human hemoglobin and ferric chloride, but not human holo-transferrin, as an iron source for in vitro growth. Analysis of the C. perfringens strain 13 genome sequence identified a putative heme acquisition system encoded by an iron-regulated surface gene region that we have named the Cht (Clostridium perfringensheme transport) locus. This locus comprises eight genes that are co-transcribed and includes genes that encode NEAT domain-containing proteins (ChtD and ChtE) and a putative sortase (Srt). The ChtD, ChtE and Srt proteins were shown to be expressed in JIR325 cells grown under iron-limited conditions and were localized to the cell envelope. Moreover, the NEAT proteins, ChtD and ChtE, were found to bind heme. Both chtDE and srt mutants were constructed, but these mutants were not defective in hemoglobin or ferric chloride utilization. They were, however, attenuated for virulence when tested in a mouse myonecrosis model, although the virulence phenotype could not be restored via complementation and, as is common with such systems, secondary mutations were identified in these strains. In summary, this study provides evidence for the functional redundancies that occur in the heme transport pathways of this life threatening pathogen.
| Original language | English |
|---|---|
| Article number | 0162981 |
| Number of pages | 26 |
| Journal | PLoS ONE |
| Volume | 11 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 16 Sep 2016 |
Keywords
- heme
- clostridium perfringens
- genetic loci
- staphylococcus aureus
- polymerase chain reaction
- bacillus anthracis
- plasmid construction
- recombinant proteins
Cite this
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The NEAT domain-containing proteins of Clostridium perfringens bind heme. / Choo, Jocelyn M.; Cheung, Jackie K.; Wisniewski, Jessica A.; Steer, David L.; Bulach, Dieter M.; Hiscox, Thomas J.; Chakravorty, Anjana; Smith, A. Ian; Gell, David A.; Rood, Julian I.; Awad, Milena M.
In: PLoS ONE, Vol. 11, No. 9, 0162981, 16.09.2016.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - The NEAT domain-containing proteins of Clostridium perfringens bind heme
AU - Choo, Jocelyn M.
AU - Cheung, Jackie K.
AU - Wisniewski, Jessica A.
AU - Steer, David L.
AU - Bulach, Dieter M.
AU - Hiscox, Thomas J.
AU - Chakravorty, Anjana
AU - Smith, A. Ian
AU - Gell, David A.
AU - Rood, Julian I.
AU - Awad, Milena M.
PY - 2016/9/16
Y1 - 2016/9/16
N2 - The ability of a pathogenic bacterium to scavenge iron from its host is important for its growth and survival during an infection. Our studies on C. perfringens gas gangrene strain JIR325, a derivative of strain 13, showed that it is capable of utilizing both human hemoglobin and ferric chloride, but not human holo-transferrin, as an iron source for in vitro growth. Analysis of the C. perfringens strain 13 genome sequence identified a putative heme acquisition system encoded by an iron-regulated surface gene region that we have named the Cht (Clostridium perfringensheme transport) locus. This locus comprises eight genes that are co-transcribed and includes genes that encode NEAT domain-containing proteins (ChtD and ChtE) and a putative sortase (Srt). The ChtD, ChtE and Srt proteins were shown to be expressed in JIR325 cells grown under iron-limited conditions and were localized to the cell envelope. Moreover, the NEAT proteins, ChtD and ChtE, were found to bind heme. Both chtDE and srt mutants were constructed, but these mutants were not defective in hemoglobin or ferric chloride utilization. They were, however, attenuated for virulence when tested in a mouse myonecrosis model, although the virulence phenotype could not be restored via complementation and, as is common with such systems, secondary mutations were identified in these strains. In summary, this study provides evidence for the functional redundancies that occur in the heme transport pathways of this life threatening pathogen.
AB - The ability of a pathogenic bacterium to scavenge iron from its host is important for its growth and survival during an infection. Our studies on C. perfringens gas gangrene strain JIR325, a derivative of strain 13, showed that it is capable of utilizing both human hemoglobin and ferric chloride, but not human holo-transferrin, as an iron source for in vitro growth. Analysis of the C. perfringens strain 13 genome sequence identified a putative heme acquisition system encoded by an iron-regulated surface gene region that we have named the Cht (Clostridium perfringensheme transport) locus. This locus comprises eight genes that are co-transcribed and includes genes that encode NEAT domain-containing proteins (ChtD and ChtE) and a putative sortase (Srt). The ChtD, ChtE and Srt proteins were shown to be expressed in JIR325 cells grown under iron-limited conditions and were localized to the cell envelope. Moreover, the NEAT proteins, ChtD and ChtE, were found to bind heme. Both chtDE and srt mutants were constructed, but these mutants were not defective in hemoglobin or ferric chloride utilization. They were, however, attenuated for virulence when tested in a mouse myonecrosis model, although the virulence phenotype could not be restored via complementation and, as is common with such systems, secondary mutations were identified in these strains. In summary, this study provides evidence for the functional redundancies that occur in the heme transport pathways of this life threatening pathogen.
KW - heme
KW - clostridium perfringens
KW - genetic loci
KW - staphylococcus aureus
KW - polymerase chain reaction
KW - bacillus anthracis
KW - plasmid construction
KW - recombinant proteins
UR - http://www.scopus.com/inward/record.url?scp=84992316363&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0162981
DO - 10.1371/journal.pone.0162981
M3 - Article
VL - 11
JO - PLoS ONE
JF - PLoS ONE
SN - 1932-6203
IS - 9
M1 - 0162981
ER -