Characterization of Pit, a
            <i>Streptococcus pneumoniae</i>
            Iron Uptake ABC Transporter

Brown, Jeremy; Gilliland, Sarah M.; Ruíz-Albert, Javier; Holden, David W.

doi:10.1128/iai.72.11.6754.2004

Cited by 10 publications

(14 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is a bit unexpected as S. suis has been reported to grow even in the absence of iron (Niven and Ekins, 2001), and thus might not express a sensoregulatory/transport machinery specific for iron. However, the old belief that respiratory chain deficient lactic acid bacteria do not need iron, or contain any active iron uptake mechanisms (Archibald, 1986), has been challenged by several studies on pathogenic streptococci (Eichenbaum et al ., 1996; Brown et al ., 2001; 2002). Moreover, our present data and one previous communication (Niven and Ekins, 2001) indicate that S. suis contains a distinct cellular iron pool.…”

Section: Discussionsupporting

confidence: 86%

Dps/Dpr ferritin‐like protein: insights into the mechanism of iron incorporation and evidence for a central role in cellular iron homeostasis in Streptococcus suis

Pulliainen

Kauko

Haataja

et al. 2005

Molecular Microbiology

View full text Add to dashboard Cite

SummaryThe Dps family members constitute a distinct group of multimeric and ferritin-like iron binding proteins (up to 500 iron atoms/12-mer) that are widespread in eubacteria and archaea and implicated in oxidative stress resistance and virulence. Despite the wealth of structural knowledge, the mechanism of iron incorporation has remained elusive. Here, we provide evidence on Dpr of the swine and human pathogen Streptococcus suis that: (i) iron incorporation proceeds by Fe(II) binding, Fe(II) oxidation and subsequent storage as Fe(III); (ii) Fe(II) atoms enter the 12-mer cavity through four hydrophilic pores; and (iii) Fe(II) atoms are oxidized inside the 12-mer cavity at 12 identical inter-subunit sites, which are structurally different but functionally equivalent to the ferroxidase centres of classical ferritins. We also provide evidence, by deleting and ectopically overexpressing Dpr, that Dpr affects cellular iron homeostasis. The key residues responsible for iron incorporation in S. suis Dpr are well conserved throughout the Dps family. A model for the iron incorporation mechanism of the Dps/Dpr ferritin-like protein is proposed.

show abstract

Section: Discussionsupporting

confidence: 86%

Dps/Dpr ferritin‐like protein: insights into the mechanism of iron incorporation and evidence for a central role in cellular iron homeostasis in Streptococcus suis

Pulliainen

Kauko

Haataja

et al. 2005

Molecular Microbiology

View full text Add to dashboard Cite

show abstract

“…3A). Susceptibility to streptonigrin was used as an indirect measure of intracellular iron concentration (Brown et al ., 2002). Growth of wild‐type S. equi was prevented by a minimal inhibitory concentration of 0.06 μM streptonigrin in THB.…”

Section: Resultsmentioning

confidence: 99%

“…Bacterial pathogens access this limited iron supply through the production of cell surface receptors for transferrin and lactoferrin, utilizing haem‐containing compounds, iron transporters, or by the synthesis and secretion of iron‐sequestering siderophores (Wandersman and Delepelaire, 2004). Streptococcus pneumoniae encodes multiple iron transporters that are important for virulence (Brown et al ., 2002) and a cell‐surface lactoferrin receptor (Hakansson et al ., 2001). Streptococcus pyogenes utilizes haemoprotein binding and transport proteins (Lei et al ., 2002) and a multimetal transport system (Janulczyk et al ., 2003).…”

Section: Introductionmentioning

confidence: 99%

A novel streptococcal integrative conjugative element involved in iron acquisition

Heather

Holden

Steward

et al. 2008

Molecular Microbiology

View full text Add to dashboard Cite

In this study, we determined the function of a novel non-ribosomal peptide synthetase (NRPS) system carried by a streptococcal integrative conjugative element (ICE), ICESe2. The NRPS shares similarity with the yersiniabactin system found in the high-pathogenicity island of Yersinia sp. and is the first of its kind to be identified in streptococci. We named the NRPS product ‘equibactin’ and genes of this locus eqbA–N. ICESe2, although absolutely conserved in Streptococcus equi, the causative agent of equine strangles, was absent from all strains of the closely related opportunistic pathogen Streptococcus zooepidemicus. Binding of EqbA, a DtxR-like regulator, to the eqbB promoter was increased in the presence of cations. Deletion of eqbA resulted in a small-colony phenotype. Further deletion of the irp2 homologue eqbE, or the genes eqbH, eqbI and eqbJ encoding a putative ABC transporter, or addition of the iron chelator nitrilotriacetate, reversed this phenotype, implicating iron toxicity. Quantification of 55Fe accumulation and sensitivity to streptonigrin suggested that equibactin is secreted by S. equi and that the eqbH, eqbI and eqbJ genes are required for its associated iron import. In agreement with a structure-based model of equibactin synthesis, supplementation of chemically defined media with salicylate was required for equibactin production.

show abstract

“…For instance, for S. pneumoniae iron transporter loss of PiaA has stronger effects on phenotype in vitro and in mouse models than loss of PiuA and PitA [38], and for glutamine uptake ABC transporter loss of SP1241 has more marked effects in mouse models of disease than loss of SP0452 [7]. For instance, for S. pneumoniae iron transporter loss of PiaA has stronger effects on phenotype in vitro and in mouse models than loss of PiuA and PitA [38], and for glutamine uptake ABC transporter loss of SP1241 has more marked effects in mouse models of disease than loss of SP0452 [7].…”

Section: Redundancy Of S Pneumoniae Abc Transporter Functionmentioning

confidence: 99%

“…Metal uptake ABC transporters have been studied the most intensively for their effects on S. pneumoniae virulence, although the involvement of ABC transporters specific for sugars, amino acids, phosphate, and polyamines has also been characterized. Other cation uptake ABC transporters that are involved in virulence include the Piu, Pia, and Pit iron transporters, and the AdcA and AdcAII zinc transporters [5,38,39]. As a consequence, deletion of either the complete psaABC operon or the manganese SBP PsaA has marked affects on S. pneumoniae virulence [30,43,74,75] in different murine models of infection, and PsaA is recognized as one of the major S. pneumoniae virulence factors.…”

Section: Role In Virulencementioning

confidence: 99%