A comparative genomic view of clostridial sporulation and physiology

Paredes, Carlos J.; Alsaker, Keith V.; Papoutsakis, Eleftherios T.

doi:10.1038/nrmicro1288

Cited by 305 publications

(364 citation statements)

References 111 publications

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“…C. botulinum Hall A lacks homologs of the kin histidine kinases, the phosphorelay system (spo0F and spo0B), and the rap phosphatases. Virtually all of these genes are also absent from other sequenced clostridia (for review, see Paredes et al 2005). The C. botulinum genome carries five orphan kinases (CBO0336, CBO0340, CBO0780, CBO1120, and Germination of spores is believed to be mediated by receptors that reside in the inner spore membrane, which are encoded by tricistronic operons.…”

Section: Sporulation and Germinationmentioning

confidence: 99%

Genome sequence of a proteolytic (Group I) Clostridium botulinum strain Hall A and comparative analysis of the clostridial genomes

Sebaihia¹,

Peck²,

Minton³

et al. 2007

Genome Res.

234

215

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Clostridium botulinum is a heterogeneous Gram-positive species that comprises four genetically and physiologically distinct groups of bacteria that share the ability to produce botulinum neurotoxin, the most poisonous toxin known to man, and the causative agent of botulism, a severe disease of humans and animals. We report here the complete genome sequence of a representative of Group I (proteolytic) C. botulinum (strain Hall A, ATCC 3502). The genome consists of a chromosome (3,886,916 bp) and a plasmid (16,344 bp), which carry 3650 and 19 predicted genes, respectively. Consistent with the proteolytic phenotype of this strain, the genome harbors a large number of genes encoding secreted proteases and enzymes involved in uptake and metabolism of amino acids. The genome also reveals a hitherto unknown ability of C. botulinum to degrade chitin. There is a significant lack of recently acquired DNA, indicating a stable genomic content, in strong contrast to the fluid genome of Clostridium difficile, which can form longer-term relationships with its host. Overall, the genome indicates that C. botulinum is adapted to a saprophytic lifestyle both in soil and aquatic environments. This pathogen relies on its toxin to rapidly kill a wide range of prey species, and to gain access to nutrient sources, it releases a large number of extracellular enzymes to soften and destroy rotting or decayed tissues.

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Section: Sporulation and Germinationmentioning

confidence: 99%

Genome sequence of a proteolytic (Group I) Clostridium botulinum strain Hall A and comparative analysis of the clostridial genomes

Sebaihia¹,

Peck²,

Minton³

et al. 2007

Genome Res.

234

215

View full text Add to dashboard Cite

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“…Both Bacillus and Clostridium species form spores under unfavourable environmental conditions (Paredes et al, 2005;Piggot, 1996;Piggot & Hilbert, 2004;Sauer et al, 1995;Stephenson & Lewis, 2005). These spores return to normal vegetative growth, a process called germination, upon encountering favourable environmental conditions Setlow, 2003).…”

Section: Introductionmentioning

confidence: 99%

Dissecting interactions between nucleosides and germination receptors in Bacillus cereus 569 spores

et al. 2010

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Bacillus cereus 569 spores germinate either with inosine as a sole germinant or with a combination of nucleosides and L-alanine. Whereas the inosine-only germination pathway requires the presence of two different germination receptors (GerI and GerQ) to be activated, the nucleoside/alanine germination pathway only needs one of the two receptors. To differentiate how nucleoside recognition varies between the inosine-only germination pathway and the nucleoside/ alanine germination pathway, we tested 61 purine analogues as agonists and antagonists of the two pathways in wild-type, DgerI and DgerQ spores. The structure-activity relationships of germination agonists and antagonists suggest that the inosine-only germination pathway is restricted to recognize a single germinant (inosine), but can be inhibited in predictable patterns by structurally distinct purine nucleosides. B. cereus spores encoding GerI as the only nucleoside receptor (DgerQ mutant) showed a germination inhibition profile similar to wild-type spores treated with inosine only. Thus, GerI seems to have a well-organized binding site that recognizes inosine and inhibitors through specific substrate-protein interactions. Structure-activity analysis also showed that the nucleoside/alanine germination pathway is more promiscuous toward purine nucleoside agonists, and is only inhibited by hydrophobic analogues. B. cereus spores encoding GerQ as the only nucleoside receptor (DgerI mutant) behaved like wild-type spores treated with inosine and L-alanine. Thus, the GerQ receptor seems to recognize substrates in a more flexible binding site through non-specific interactions. We propose that the GerI receptor is responsible for germinant detection in the inosine-only germination pathway. On the other hand, supplementing inosine with L-alanine allows bypassing of the GerI receptor to activate the more flexible GerQ receptor.

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“…The gene regulation network that detects sporulation-conducive conditions and either activates or suppresses Spo0A (as appropriate according to the conditions) is well-defined in B. subtilis [8,9,10] and, while some distinctions exist (most notably the absence of a nutrient-starvation trigger in C. acetobutylicum), there is a great deal of overlap between this network and what is known of the corresponding one in C. acetobutylicum [8,11] (and indeed in other clostridial species), allowing us to draw on previous modelling work of B. subtilis [9] to create a suitable model for C. acetobutylicum. Furthermore, transcription of certain of the enzymes governing solventogenesis is under the control of Spo0A: putative binding sites have been identified in the region of their transcription start sites [12,13].…”

Section: Introductionmentioning

confidence: 99%

The putative influence of the agr operon upon survival mechanisms used by Clostridium acetobutylicum

Jabbari

Steiner

Heap

et al. 2013

Mathematical Biosciences

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The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.ukThe putative influence of the agr operon upon survival mechanisms used by Clostridium acetobutylicum AbstractThe bacterium Clostridium acetobutylicum produces acids as an energy-yielding process during exponential growth. An acidic environment, however, is toxic to the cells and two survival mechanisms are in place to prevent them from dying. Firstly, during a solventogenesis phase, the cells take up these acids and convert them to solvents, thus raising the environmental pH. Secondly, the cells undergo sporulation to form highly resistant spores capable of surviving extreme conditions. One possible regulatory mechanism for these processes is the accessory gene regulatory (agr ) quorum-sensing system, which is thought to coordinate cell population density with cell phenotype. We model this system to monitor its putative effect upon solventogenesis and the sporulation-initiation network responsible for triggering spore formation. We demonstrate that a high population density should be able to induce both solventogenesis and sporulation, with variations to the parameter set allowing sporulation alone to be triggered; additional distinct signals are capable of restoring the solventogenic response. We compare the agr system of C. acetobutylicum with that of Staphylococcus aureus in order to investigate why the differences in feedback between the two systems may have evolved. Our findings indicate that, depending upon the mechanism of interaction between the agr system and the sporulation-initiation network, the clostridial agr circuitry may be in place either to moderate the number of spores that are formed (in order for this number to reflect the urgency of the situation), or simply as an energy-saving strategy.

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A comparative genomic view of clostridial sporulation and physiology

Cited by 305 publications

References 111 publications

Genome sequence of a proteolytic (Group I) Clostridium botulinum strain Hall A and comparative analysis of the clostridial genomes

Genome sequence of a proteolytic (Group I) Clostridium botulinum strain Hall A and comparative analysis of the clostridial genomes

Dissecting interactions between nucleosides and germination receptors in Bacillus cereus 569 spores

The putative influence of the agr operon upon survival mechanisms used by Clostridium acetobutylicum

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