A Laterally Acquired Galactose Oxidase-Like Gene Is Required for Aerial Development during Osmotic Stress in Streptomyces coelicolor

Liman, Recep; Facey, Paul D.; Keulen, Geertje van; Dyson, Paul; Sol, Ricardo Del

doi:10.1371/journal.pone.0054112

Cited by 31 publications

(27 citation statements)

References 40 publications

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“…cslA appears to be the first gene of a bicistronic operon that also includes glxA , encoding a galactose oxidase required for proper aerial development during osmotic stress. Although the two genes are cotranscribed, glxA is also expressed from an independent promoter within the clsA coding sequence (33). …”

Section: Resultsmentioning

confidence: 99%

Genes Required for Aerial Growth, Cell Division, and Chromosome Segregation Are Targets of WhiA before Sporulation in Streptomyces venezuelae

Bush

Bibb

Chandra

et al. 2013

mBio

110

156

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WhiA is a highly unusual transcriptional regulator related to a family of eukaryotic homing endonucleases. WhiA is required for sporulation in the filamentous bacterium Streptomyces, but WhiA homologues of unknown function are also found throughout the Gram-positive bacteria. To better understand the role of WhiA in Streptomyces development and its function as a transcription factor, we identified the WhiA regulon through a combination of chromatin immunoprecipitation-sequencing (ChIP-seq) and microarray transcriptional profiling, exploiting a new model organism for the genus, Streptomyces venezuelae, which sporulates in liquid culture. The regulon encompasses ~240 transcription units, and WhiA appears to function almost equally as an activator and as a repressor. Bioinformatic analysis of the upstream regions of the complete regulon, combined with DNase I footprinting, identified a short but highly conserved asymmetric sequence, GACAC, associated with the majority of WhiA targets. Construction of a null mutant showed that whiA is required for the initiation of sporulation septation and chromosome segregation in S. venezuelae, and several genes encoding key proteins of the Streptomyces cell division machinery, such as ftsZ, ftsW, and ftsK, were found to be directly activated by WhiA during development. Several other genes encoding proteins with important roles in development were also identified as WhiA targets, including the sporulation-specific sigma factor σWhiG and the diguanylate cyclase CdgB. Cell division is tightly coordinated with the orderly arrest of apical growth in the sporogenic cell, and filP, encoding a key component of the polarisome that directs apical growth, is a direct target for WhiA-mediated repression during sporulation.

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Section: Resultsmentioning

confidence: 99%

Genes Required for Aerial Growth, Cell Division, and Chromosome Segregation Are Targets of WhiA before Sporulation in Streptomyces venezuelae

Bush

Bibb

Chandra

et al. 2013

mBio

110

156

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“…GlxA is a newly characterized member of the AA5 family of mono-copper oxidase possessing a Tyr-Cys cross-linked redox cofactor (30). A glxA null mutant blocks development and abolishes pellet formation coinciding with the loss of glycan deposition at hyphal tips, the same phenotype as observed with the cslA deletion (30,33). This is consistent with a model whereby CslA and GlxA cooperatively function in glycan deposition at the hyphal tip and are jointly responsible for the formation of reproductive aerial structures and, in liquid environments, for the formation of pellets (30).…”

mentioning

confidence: 92%

Heterogeneity in the Histidine-brace Copper Coordination Sphere in Auxiliary Activity Family 10 (AA10) Lytic Polysaccharide Monooxygenases

Chaplin

Wilson

Hough

et al. 2016

Journal of Biological Chemistry

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Copper-dependent lytic polysaccharide monooxygenases (LPMOs) are enzymes that oxidatively deconstruct polysaccharides. The active site copper in LPMOs is coordinated by a histidine-brace. This utilizes the amino group and side chain of the N-terminal His residue with the side chain of a second His residue to create a T-shaped arrangement of nitrogen ligands. We report a structural, kinetic, and thermodynamic appraisal of copper binding to the histidine-brace in an auxiliary activity family 10 (AA10) LPMO from Streptomyces lividans (SliLPMO10E). Unexpectedly, we discovered the existence of two apo-SliLPMO10E species in solution that can each bind copper at a single site with distinct kinetic and thermodynamic (exothermic and endothermic) properties. The experimental EPR spectrum of copper-bound SliLPMO10E requires the simulation of two different line shapes, implying two different copper-bound species, indicative of three and two nitrogen ligands coordinating the copper. Amino group coordination was probed through the creation of an N-terminal extension variant (SliLPMO10E-Ext). The kinetics and thermodynamics of copper binding to SliLPMO10E-Ext are in accord with copper binding to one of the apo-forms in the wild-type protein, suggesting that amino group coordination is absent in the two-nitrogen coordinate form of SliLPMO10E. Copper binding to SliLPMO10B was also investigated, and again it revealed the presence of two apo-forms with kinetics and stoichiometry of copper binding identical to that of SliLPMO10E. Our findings highlight that heterogeneity exists in the active site copper coordination sphere of LPMOs that may have implications for the mechanism of loading copper in the cell.Lytic polysaccharide monooxygenases (LPMOs) 3 are enzymes that utilize copper as their functional active site metal and act to enhance the depolymerization of recalcitrant polysaccharides in nature such as cellulose and chitin (1, 2). Identification and characterization of members of this cuproenzyme family from fungal and bacterial species have gathered pace in recent years due in part to their promising uses in biorefinery applications of biomass to derive second generation biofuels (2, 3). LPMOs are classed into auxiliary activity (AA) families in the CAZy (carbohydrate active enzyme) database with four AA families, AA9, AA10, AA11, and AA13 identified so far (4). AA9 (formerly GH61) and AA10 (formerly CBM33) families have been the most extensively studied, with AA9 members having activity for cellulose, hemicellulose, and cellodextrin substrates (5-8) and AA10 members having activity with either cellulose or chitin substrates (9, 10). The AA11 and AA13 families are the most recently discovered, and so far have been determined to have activity with chitin and starch substrates, respectively (11, 12). All LPMOs coordinate a single copper ion by three nitrogen ligands to from the active site. Two of these are provided from the amino group (Nt) and side chain of the N-terminal His with the third from a second His side chain to giv...

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“…However, the physiological role of this protein remains elusive. Recently, Liman et al (2013) reported that Glx is required for aerial hyphae formation and for their further differentiation into hyphal spores in Streptomyces coelicolor . Similarly, this protein might play an important role in plant cell differentiation or in morphological changes.…”

Section: Resultsmentioning

confidence: 99%

A small-scale proteomic approach reveals a survival strategy, including a reduction in alkaloid biosynthesis, in Hyoscyamus albus roots subjected to iron deficiency

et al. 2013

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Hyoscyamus albus is a well-known source of the tropane alkaloids, hyoscyamine and scopolamine, which are biosynthesized in the roots. To assess the major biochemical adaptations that occur in the roots of this plant in response to iron deficiency, we used a small-scale proteomic approach in which 100 mg of root tips were treated with and without Fe, respectively, for 5 days. Two-dimensional mini gels showed that 48 spots were differentially accumulated between the two conditions of Fe availability and a further 36 proteins were identified from these spots using MALDI-QIT-TOF mass spectrometry. The proteins that showed elevated levels in the roots lacking Fe were found to be associated variously with carbohydrate metabolism, cell differentiation, secondary metabolism, and oxidative defense. Most of the proteins involved in carbohydrate metabolism were increased in abundance, but mitochondrial NAD-dependent malate dehydrogenase was decreased, possibly resulting in malate secretion. Otherwise, all the proteins showing diminished levels in the roots were identified as either Fe-containing or ATP-requiring. For example, a significant decrease was observed in the levels of hyoscyamine 6β-hydroxylase (H6H), which requires Fe and is involved in the conversion of hyoscyamine to scopolamine. To investigate the effects of Fe deficiency on alkaloid biosynthesis, gene expression studies were undertaken both for H6H and for another Fe-dependent protein, Cyp80F1, which is involved in the final stage of hyoscyamine biosynthesis. In addition, tropane alkaloid contents were determined. Reduced gene expression was observed in the case of both of these proteins and was accompanied by a decrease in the content of both hyoscyamine and scopolamine. Finally, we have discussed energetic and Fe-conservation strategies that might be adopted by the roots of H. albus to maintain iron homeostasis under Fe-limiting conditions.

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A Laterally Acquired Galactose Oxidase-Like Gene Is Required for Aerial Development during Osmotic Stress in Streptomyces coelicolor

Cited by 31 publications

References 40 publications

Genes Required for Aerial Growth, Cell Division, and Chromosome Segregation Are Targets of WhiA before Sporulation in Streptomyces venezuelae

Genes Required for Aerial Growth, Cell Division, and Chromosome Segregation Are Targets of WhiA before Sporulation in Streptomyces venezuelae

Heterogeneity in the Histidine-brace Copper Coordination Sphere in Auxiliary Activity Family 10 (AA10) Lytic Polysaccharide Monooxygenases

A small-scale proteomic approach reveals a survival strategy, including a reduction in alkaloid biosynthesis, in Hyoscyamus albus roots subjected to iron deficiency

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