Identification and Structure of the Anti-sigma Factor-binding Domain of the Disulphide-stress Regulated Sigma Factor σR from Streptomyces coelicolor

Li, Wei; Stevenson, C.E.M.; Burton, Nicolas P.; Jakimowicz, Piotr; Paget, Mark S. B.; Buttner, Mark J.; Lawson, David M.; Kleanthous, Colin

doi:10.1016/s0022-2836(02)00948-8

Cited by 59 publications

(58 citation statements)

References 59 publications

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“…Whether this reflects the natural situation whereby free and active ECF sigma factors are readily turned over, perhaps to ensure that continued activation of target genes is dependent upon ongoing synthesis of the sigma factors (an indicator that they are still required) and allowing the system to quickly respond to absence of inducing conditions, is unclear. Certainly, proteolysis and proteolytic control of sigma factor activity have been reported in bacteria (15,25,34 [23]) though generally via interaction with region 2 of these factors (1,23). The AsiA anti-sigma factor of phage T4 that controls 70 activity in E. coli is known to bind region 4 and to interfere with promoter binding (44), though AsiA is a soluble protein and it's not clear that a membranebound anti-sigma factor binding to the same region of a sigma factor would act in the same fashion.…”

Section: Discussionmentioning

confidence: 99%

FpvIR Control of fpvA Ferric Pyoverdine Receptor Gene Expression in Pseudomonas aeruginosa : Demonstration of an Interaction between FpvI and FpvR and Identification of Mutations in Each Compromising This Interaction

Rédly

Poole

2005

J Bacteriol

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FpvR is a presumed cytoplasmic membrane-associated anti-sigma factor that controls the activities of extracytoplasmic function sigma factors PvdS and FpvI responsible for transcription of pyoverdine biosynthetic genes and the ferric pyoverdine receptor gene, fpvA, respectively. Using deletion analysis and an in vivo bacterial two-hybrid system, FpvR interaction with these factors was confirmed and shown to involve the cytoplasmic N-terminal 67 amino acid resides of FpvR. FpvR bound specifically to a C-terminal region of FpvI corresponding to region 4 of the 70 family of sigma factors. FpvR and FpvI mutant proteins compromised for this interaction were generated by random and site-directed PCR mutagenesis and invariably contained secondary structure-altering proline substitution in predicted ␣-helices within the FpvR N terminus or FpvI region 4. PvdS was shown to bind to the same N-terminal region of FpvR, and FpvR mutations compromising FpvI binding also compromised PvdS binding, although some mutations had a markedly greater impact on PvdS binding. Apparently, these two factors bind to FpvR in a substantially similar but not identical fashion. Intriguingly, defects in FpvR binding correlated with a substantial drop in yields of the FpvI and to a lesser extent PvdS factors, suggesting that FpvR-bound FpvI and PvdS are stable while free and active sigma factor is prone to turnover.Iron is an essential nutrient whose acquisition by Pseudomonas aeruginosa is often facilitated by high-affinity iron-chelating molecules termed siderophores that, together with cell surface receptors specific for the iron-siderophore complexes, serve to provide the organism with iron under the most nutritionally dilute conditions (35). A major siderophore produced by P. aeruginosa and, indeed, all fluorescent pseudomonads is pyoverdine, a mixed catecholate-hydroxamate siderophore characterized by a conserved dihydroxyquinoline chromophore to which is attached a peptide chain of variable length and composition (5, 30). This variation likely explains the noted specificity vis-à-vis pyoverdine utilization by Pseudomonas spp., where a given strain will often use only its own pyoverdine and not that of other Pseudomonas strains (6, 14), and suggests that the peptide moiety is involved in receptor recognition and binding. A number of genes for the biosynthesis of pyoverdine have been identified to date in P. aeruginosa (19, 20, 26-28, 32, 48-50) and cluster within a region of the chromosome referred to as the pvd locus (47), although an operon implicated in synthesis of the chromophore, pvcABCD (45, 46), occurs elsewhere. Still, a pvd gene (pvdL) has also been reported to function in chromophore synthesis (31), raising questions about the necessity of the pvc genes in this.The ferric pyoverdine receptor of P. aeruginosa PAO1 (FpvA or FpvAI) is a ca. 90-kDa outer membrane protein inducible under conditions of iron limitation (29, 36) and encoded by the fpvA gene (37) that is also found in the pvd locus (32). FpvA exhibits features typical of...

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Section: Discussionmentioning

confidence: 99%

FpvIR Control of fpvA Ferric Pyoverdine Receptor Gene Expression in Pseudomonas aeruginosa : Demonstration of an Interaction between FpvI and FpvR and Identification of Mutations in Each Compromising This Interaction

Rédly

Poole

2005

J Bacteriol

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“…Because most transcription in rapidly growing cells involves stable RNA synthesis, and rRNA promoters are sensitive to Rif, the addition of Rif might cause a rapid increase in the availability of RNAP as continued initiation at rRNA promoters is blocked. RNAP and RsrA are in competition for σ R binding (Li et al, 2002), and so the outcome might be an increase in the concentration of σ R -RNAP holoenzyme, leading to an increase in σ activity. A related 'passive' model was proposed to explain why amino acid biosynthetic promoters are induced during amino acid starvation: the inhibition of rRNA synthesis by ppGpp (in concert with DksA), is thought to increase available RNAP levels, thereby stimulating transcription from amino acid promoters that have slow RNAP association rates (Zhou and Jin, 1998;Barker et al, 2001).…”

Section: Why Is σ R Activity Induced By Rif?mentioning

confidence: 99%

“…Perhaps the best-characterized ECF sigma factor in S. coelicolor is σ R , which controls the cytoplasmic disulphide stress response (Paget et al ., 1998;Kang et al ., 1999). In response to unwanted disulphide bond formation in the cytoplasm, the activity of σ R increases through the oxidative inactivation of its zinc-binding antisigma factor RsrA (Kang et al ., 1999;Li et al ., 2002;. σ R is then free to bind to core RNAP and activate the expression of the σ R regulon, which numbers at least 30 transcription units and encodes several enzymes, including the thiore-doxin system, that help restore the thiol-disulphide redox balance (Paget et al ., 2001a).…”

Section: Introductionmentioning

confidence: 99%

The RNA polymerase‐binding protein RbpA confers basal levels of rifampicin resistance on Streptomyces coelicolor

Newell

Thomas

Brekasis

et al. 2006

Molecular Microbiology

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SummaryRbpA is an RNA polymerase-binding protein that occurs in the actinomycete family of bacteria and is regulated by the disulphide stress-response sigma factor, σ σ σ σ R , in Streptomyces coelicolor . Here we demonstrate that rbpA null mutants exhibit a slow-growth phenotype and are particularly sensitive to the transcription inhibitor rifampicin. Strikingly, transcription mapping experiments revealed that rbpA expression is induced upon exposure of S. coelicolor to rifampicin and that this, in part, involves an increase in the activity of σ σ σ σ R . In contrast, the ribosomal RNA operon promoter rrnDp3 , which is recognized by the vegetative sigma factor σ σ σ σ HrdB , was strongly inhibited by rifampicin. Reconstitution of RNAP from an rbpA null mutant with purified RbpA revealed that RbpA stimulates transcription from rrnDp3 , even in the presence of rifampicin. The data presented suggest that RbpA confers basal levels of rifampicin resistance and is a novel regulator of rRNA synthesis in S. coelicolor .

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“…Often, these include a trans-membrane protein with an extracytoplasmic sensory domain and an intracellular inhibitory domain functioning as an anti-sigma factor that binds and inhibits the cognate sigma factor. Although only a limited number of examples have been shown, direct interaction with sigma factor and anti-sigma factor has been reported for E. coli SigE and RseA (Campbell et al, 2003;Raivio & Silhavy, 2001), FecI and FecR (Enz et al, 2000), P. aeruginosa AlgU and MucA (Rowen & Deretic, 2000), Rhodobacter sphaeroides SigE and ChrR (Newman et al, 2001), S. coelicolor SigR and RsrA (Li et al, 2002) and Myxococcus xanthus CarQ and CarR (Browning et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Interaction of Bacillus subtilis extracytoplasmic function (ECF) sigma factors with the N-terminal regions of their potential anti-sigma factors

et al. 2004

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Extracytoplasmic function (ECF) sigma factors constitute a diverse family of proteins, within the class of the sigma 70 subunit of RNA polymerase. Most members of the family studied to date are known to regulate gene expression in response to stress conditions. The Bacillus subtilis genome encodes at least 17 distinct sigma factors, seven of which are members of the ECF subfamily. Among these, five sigma factors, namely SigV, SigW, SigX, SigY and SigM, are encoded by the first genes of the cognate sigma operons. Disruption or repressed expression of the downstream gene(s) resulted in transcriptional activation of the cognate sigma operon. Moreover, in vivo protein-protein interaction analyses by yeast two-hybrid experiments indicated that these immediate downstream gene products bind the cognate ECF sigma factor, suggesting that they function as anti-sigma factors by capturing sigma factor on the inner surface of the cytoplasmic membrane. Interaction with other sigma factors was not observed. The results presented here also show that these anti-sigma factors interact with ECF sigma factors through their N-terminal region, implying that the N-terminal domain resides inside the cytoplasmic membrane.

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Identification and Structure of the Anti-sigma Factor-binding Domain of the Disulphide-stress Regulated Sigma Factor σR from Streptomyces coelicolor

Cited by 59 publications

References 59 publications

FpvIR Control of fpvA Ferric Pyoverdine Receptor Gene Expression in Pseudomonas aeruginosa : Demonstration of an Interaction between FpvI and FpvR and Identification of Mutations in Each Compromising This Interaction

FpvIR Control of fpvA Ferric Pyoverdine Receptor Gene Expression in Pseudomonas aeruginosa : Demonstration of an Interaction between FpvI and FpvR and Identification of Mutations in Each Compromising This Interaction

The RNA polymerase‐binding protein RbpA confers basal levels of rifampicin resistance on Streptomyces coelicolor

Interaction of Bacillus subtilis extracytoplasmic function (ECF) sigma factors with the N-terminal regions of their potential anti-sigma factors

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