Site-directed mutagenesis of the A-factor receptor protein:

Sugiyama, Masakazu; Onaka, Hiroyasu; Nakagawa, Taishiro; Horinouchi, Sueharu

doi:10.1016/s0378-1119(98)00487-9

Cited by 35 publications

(13 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

Section: Resultsmentioning

confidence: 99%

“…All the cbutyrolactone receptor proteins contain a helix-turn-helix DNA-binding motif near the N terminus and a tryptophan (W) residue in the middle, for example at the 119 position in ArpA. The former was important for binding of ArpA to the promoter of adpA, while the latter was crucial for binding of A-factor to ArpA (Sugiyama et al, 1998).Orf82 (named SrrA) is the most probable candidate, because its pI value (6.07) is similar to those of the typical c-butyrolactone receptors (ArpA, 5.14; BarA, 5.08; FarA, 5.29). In S. griseus, the afsA-arpA double mutant produced streptomycin, because the global activator gene adpA was not repressed under arpA mutation without A-factor.…”

mentioning

confidence: 99%

See 1 more Smart Citation

γ-Butyrolactone autoregulator-receptor system involved in lankacidin and lankamycin production and morphological differentiation in Streptomyces rochei

et al. 2007

View full text Add to dashboard Cite

An afsA homologue (srrX) and three c-butyrolactone receptor gene homologues (srrA, srrB and srrC) are coded on the giant linear plasmid pSLA2-L in Streptomyces rochei 7434AN4, a producer of two polyketide antibiotics, lankacidin and lankamycin. Construction of gene disruptants and their phenotypic study revealed that srrX and srrA make a c-butyrolactone receptor system in this strain. Addition of a c-butyrolactone fraction to an srrX-deficient mutant restored the production of lankacidin and lankamycin, indicating that the SrrX protein is not necessary for this event. In addition to a positive effect on antibiotic production, srrX showed a negative effect on morphological differentiation. The receptor gene srrA reversed both effects of srrX, while the second receptor gene homologue srrC had only a positive function in spore formation. Furthermore, disruption of the third homologue srrB greatly increased the production of lankacidin and lankamycin. Electron microscopic analysis showed that aerial mycelium formation stopped at a different stage in the srrA and srrC mutants. Overall, these results indicated that srrX, srrA, srrB and srrC constitute a complex regulatory system for antibiotic production and morphological differentiation in S. rochei. INTRODUCTIONThe filamentous Gram-positive soil bacteria of the genus Streptomyces are characterized by three distinct properties: linear chromosome, complex morphological differentiation and ability to produce varieties of secondary metabolites including antibiotics. Antibiotic biosynthetic genes in Streptomyces species usually form a condensed gene cluster on the chromosome. However, several giant linear plasmids encoding an antibiotic gene cluster(s) have been isolated: SCP1 in Streptomyces coelicolor A3(2) carries the biosynthetic gene cluster for methylenomycin (Bentley et al., 2004;Chater & Bruton, 1985;Kinashi et al., 1987;Redenbach et al., 1998), pPZG103 in Streptomyces rimosus has that for oxytetracycline (Gravius et al., 1994; Pandza et al., 1998) and pSLA2-L in Streptomyces rochei has those for lankacidin and lankamycin (Arakawa et al., 2005(Arakawa et al., , 2006Mochizuki et al., 2003;Suwa et al., 2000).S. rochei strain 7434AN4 contains three large linear plasmids (pSLA2-L, -M and -S) (Kinashi et al., 1994) and produces two structurally unrelated polyketide antibiotics, the 17-membered macrocyclic lankacidin and the 14-membered macrolide lankamycin (Fig. 1a). We have been studying the function of the largest linear plasmid pSLA2-L in antibiotic production, and finally determined its 210 614 bp nucleotide sequence (Mochizuki et al., 2003). It was revealed that pSLA2-L contains an unusually condensed gene organization for secondary metabolism (Fig. 1b); two type I PKS gene clusters for lankacidin (lkc, orf4-orf18) and lankamycin (lkm, orf24-orf53), a cryptic type II PKS gene cluster (roc, orf62-orf70) and a carotenoid biosynthetic gene cluster (crt, orf104-orf110). In addition, many regulatory genes were identified on pSLA2-L, including all the homologues in t...

show abstract

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

γ-Butyrolactone autoregulator-receptor system involved in lankacidin and lankamycin production and morphological differentiation in Streptomyces rochei

et al. 2007

View full text Add to dashboard Cite

show abstract

“…The difficulty for this step is probably associated with the volatileness, the high solubility in water and/or the degradation of the aldehyde formed, making difficult its isolation. However, as this type of reaction is already reported in the literature employing the reagents K 2 OsO 4 , N-methylmorpholine N-oxide (NMO) and NaIO 4 to cleave the terminal double bond (transformation of the compound 19 in the A-factor, as outlined in scheme 5), we have the conviction that our aim could be accomplished with modifications on the reactional conditions and/or of the reagents which are necessary to realize with success this final step.…”

Section: Vb-e (5)mentioning

confidence: 89%

“…1,2 "Streptomycetes" são bactérias Gram-positivas, caracterizadas pela capacidade de produzir uma grande variedade de metabólitos secundários, entre eles numerosos tipos de antibióticos comerciais e substâncias biologicamente ativas. 3,4 Todos os organismos necessitam produzir energia e alterar um grande número de compostos orgânicos, para poderem sobreviver, crescer e reproduzir. Isto é realizado através de um processo integrado de enzimas e reações químicas específicas, denominado metabolismo, sendo que os caminhos envolvidos são chamados de vias metabólicas.…”

Section: I1 As Bactérias Streptomyces E Os Fatores Autoreguladoresunclassified

“…Sua estrutura química foi posteriormente confirmada através de um processo sintético, 8 entretanto a sua estereoquímica absoluta ainda provocava contradições. Posteriormente, 12 por redução com NaBH 4 , o fator-A foi transformado em outras butirolactonas (6 e 9), conforme mostrado no esquema 1. Como os derivados do ácido paracônico (12) são materiais de partida importantes para a preparação de diversos produtos naturais biologicamente ativos, 13 grandes esforços têm sido dedicados para realizar a sua síntese enantiosseletiva.…”

Section: I2 O Fator-aunclassified

See 1 more Smart Citation

Estudos sobre a síntese de butirolactonas auto-reguladoras de bactérias Streptomyces.

Sairre¹

View full text Add to dashboard Cite

À minha grande amiga Erika, pela cumplicidade em todos os momentos, pelas discussões, sugestões, carinho, sinceridade e pela ótima convivência desde a graduação, iniciação científica até a conclusão deste trabalho; Ao meu grande amigo Kleber, pela convivência, amizade e contribuição neste trabalho; À Mércia, pela sincera amizade, dedicação, consideração e pelas análises de HPLC; À Virginia, pela amizade e incontestável competência na obtenção dos espectros de RMN; À Cristina, pelas análises de GC/MS; Ao Djalma, pela amizade e pelos espectros de IV; Aos amigos do LSO: Aline, Valquíria, Adriana, Rosângela, Susi, Juliana, Ana Lúcia, Felipe, Gilberto, Miro, Álvaro, Ricardo, Paulo, Valdemar, Adilson, Luis Carlos, Francisco, Marco Antônio, Shirley, Emílio, Giovanna, Vinícius, Daiane, Ellen, Roberta, Rodrigo (Pena), Rodrigo, Viviani e Edilene; Algumas abreviações......................................................................................................1 Resumo............................................................................................................................3 Summary..........................................................................................................................5 I. Introdução....................................................................................................................7 II. Objetivos...................................................................................................................21 III. Planejamento Sintético............................................................................................23 IV. Atividades Realizadas e Resultados Obtidos...........................................................27 V. Conclusões................................................................................................................77 VI. Parte Experimental..................................................................................................80 VII. Espectros Selecionados........................................................................................125 VIII. Referências Bibliográficas..................................................................................199 A maioria desses compostos com propriedades autoreguladoras possui como característica estrutural comum a presença de um esqueleto γ-butirolactônico 2,3-dissubstituído, mas mostram pequenas diferenças estruturais na cadeia lateral.Essas moléculas, cujas estruturas são mostradas abaixo, são classificadas nos tipos:"virginiae" butanolidas (VB) A-E (1-5), fatores de Gräfe (6-7), butanolida IM-2 (8), o fator-I (9) e o fator-A (10). Gräfe's factors (6-7), IM-2 butanolide (8), I-factor (9) and A-factor (10). VB-B (2)OH VB-B (2)OHIn this work, studies were developed with aim to test a new synthetic pathway to obtain A-factor (10) analogous, which by enantioselective reduction of the carbonyl group of the side chain can be converted into others butyrolactone autoregulators. Summary Estudos sobre a síntese de butirolactona...

show abstract

Characterisation of a γ-butyrolactone receptor of Streptomyces tacrolimicus: effect on sporulation and tacrolimus biosynthesis

Salehi-Najafabadi

Barreiro

Martínez-Castro

et al. 2011

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

Streptomyces tacrolimicus (ATCC 55098) was reported to produce the immunosuppressant tacrolimus. The wild-type strain sporulates sparsely and produces very low levels of this immunosuppressant. The lack of genetic knowledge of this strain has hampered strain improvement. In this work, we have cloned the gene encoding a γ-butyrolactone receptor protein (Gbr). The gbr gene is linked to two genes encoding two subunits of the dihydroxyacetone kinase, putatively involved in the biosynthesis of the dihydroxyacetone phosphate precursor of γ-butyrolactone but is not flanked by γ-butyrolactone synthetase genes. The Gbr protein was overexpressed in Escherichia coli and purified. Electrophoretic mobility shift assays showed that Gbr binds to a specific autoregulatory element sequence located 338 bp upstream of the gbr gene, indicating that its expression is self-regulated. The deletion mutant Δgbr showed a very early and intense sporulation in two different media. A phenotype similar to that of the wild-type strain was restored by complementation of the Δgbr mutant with a wild-type gbr allele. Duplication of the gbr gene resulted in a slower sporulation. The Δgbr mutant produced much lower amount (32%) of tacrolimus quantified by high performance liquid chromatography. This analysis, using an optimised system, allowed the resolution of tacrolimus from ascomycin and other contaminant metabolites. Our results indicate that the Gbr protein regulates negatively the sporulation and positively the production of tacrolimus.

show abstract

Site-directed mutagenesis of the A-factor receptor protein:

Cited by 35 publications

References 24 publications

γ-Butyrolactone autoregulator-receptor system involved in lankacidin and lankamycin production and morphological differentiation in Streptomyces rochei

γ-Butyrolactone autoregulator-receptor system involved in lankacidin and lankamycin production and morphological differentiation in Streptomyces rochei

Estudos sobre a síntese de butirolactonas auto-reguladoras de bactérias Streptomyces.

Characterisation of a γ-butyrolactone receptor of Streptomyces tacrolimicus: effect on sporulation and tacrolimus biosynthesis

Contact Info

Product

Resources

About