Here, Podospora leporina was isolated and cultured from Cypripedium guttatum Sw. (spotted lady’s slipper), which was designated as an endangered wildlife class 1 by the Ministry of Environment. ...Further, Podospora sp., which is found in Calanthe discolor Lindl. (Japanese hardy orchid) root is recorded as an endophytic fungus in Jeju Island, Korea. However, there is no existing record of Podospora spp. Thus, in this study, we analyzed the morphological characteristics and two molecular markers, internal transcribed spacer (ITS) and large ribosomal subunit (LSU), of P. leporina and compared these data with other relative species. Consequently, this endophytic fungal species was confirmed as an unrecorded species in Korea, so we presented cultural characteristics and microstructures, such as the conidia of P. leporina.
Tubulysins are a group of secondary metabolites produced by myxobacteria that inhibit the function of the eukayotic cytoskeleton. We developed a pair of PCR primers that specifically amplified ...tubulysin biosynthetic genes. Using these primers, eight out of the eighty-one strains of myxobacteria belonging to the Cystobacteraceae family that harbored putative tubulysin biosynthetic genes were screened through PCR analysis. The selected strains included two Archangium gephyra, two Stigmatella sp., two Vitiosangium cumulatum, and two unidentified myxobacteria. LC-MS analysis of the culture extracts from the selected strains revealed that A. gephyra KYC4066 produced putative tubulysin A and B. KCI Citation Count: 1
Argyrins are a group of anticancer and antibacterial octapeptide bioactive substances isolated from myxobacteria. In this study, we showed that the myxobacterium Archangium gephyra MEHO_001, isolated ...in Korea, produces argyrins A and B. MEHO_001 cells tend to aggregate when cultured in liquid media. Hence, a dispersion mutant, MEHO_002, was isolated from MEHO_001. The MEHO_002 strain produced approximately 3.5 times more argyrins than that produced by the wild-type strain MEHO_001. We determined the whole-genome sequence of A. gephyra MEHO_002 and identified a putative argyrin biosynthetic gene cluster comprising five genes, arg1-arg5, encoding non-ribosomal peptide synthases and tailoring enzymes. Inactivation of arg2 by plasmid insertion disrupted argyrin production. The amino acid sequences of the proteins encoded by arg2-arg5 of A. gephyra MEHO_002 were 90-98% similar to those encoded by the argyrin biosynthetic genes of Cystobacter sp. SBCb004, an argyrin-producing myxobacterium with identical domain organization.
This research was conducted to determine the biodiversity of higher fungi at the supersite of Mt. Jeombong from July to October 2017 during the second long-term ecology research by the National ...Institute of Ecology under the management of the Ministry of Environment of Korea. Forty-three families, 74 genera, and 130 species of higher fungi were found within the permanent square area of Mt. Jeombong and a 10 m radius of the ecological flux tower. Russulaceae (54 species, 21.9%), Amanitaceae (17 species, 6.9%), and Boletaceae (17 species, 6.9%) were the top three species taxa found in mycorrhizal mushrooms. Mycenaceae (nine species, 8.5%), Polyporaceae (11 species, 4.5%), and Strophariaceae (11 species, 4.5%) were the top three species taxa found in saprophytic mushrooms. These results were analyzed and compared with those of previous fungal mushroom studies.
Tubulysins are a group of secondary metabolites produced by myxobacteria that inhibit the function of the eukayotic cytoskeleton. We developed a pair of PCR primers that specifically amplified ...tubulysin biosynthetic genes. Using these primers, eight out of the eighty-one strains of myxobacteria belonging to the Cystobacteraceae family that harbored putative tubulysin biosynthetic genes were screened through PCR analysis. The selected strains included two Archangium gephyra, two Stigmatella sp., two Vitiosangium cumulatum, and two unidentified myxobacteria. LC-MS analysis of the culture extracts from the selected strains revealed that A. gephyra KYC4066 produced putative tubulysin A and B.
Tubulysin은 다양한 암세포주에 대해 강한 항암활성을 보이는 점액세균 유래 이차대사 생리활성물질이다. 본 연구에서는 tubulysin을 생산하는 두 균주의 점액세균 Archangium gephyra MEHO_002와 MEHO_004의 유전체 분석을 통해 tubulysin 생합성 유전자들로 추정되는 유전자군을 발견하였으며, 플라스미드 삽입에 의한 ...유전자 불활성화를 통해 이들 유전자들이 tubulysin 생산과 직접 연관되어 있음을 확인하였다. A. gephyra MEHO_002와 MEHO_004 균주의 tubulysin 생합성 유전자군(tubA~tubF)은 DNA 염기서열이 서로 97% 동일하였으며, 암호화하는 단백질들의 아미노산 서열도 서로 97-100% 유사하였다. MEHO_002와 MEHO_004 균주의 tubulysin 생합성 유전자군은 tubulysin 생산 점액세균으로 알려진 Cystobacter sp. SBCb004의 tubulysin 생합성 유전자군과 DNA 염기서열이 86% 동일하였다. 유전자군의 구성은 tubZ 유전자가 존재하지 않는다는 점을 제외하고는 SBCb004의 tubulysin 생합성 유전자군 구성과 동일하였다. 각 유전자가 암호화하는 단백질의 아미노산 서열은 Cystobacter sp. SBCb004의 tubulysin 생합성 유전자가 암호화하는 단백질들과 88-97% 유사하였으며, 각 단백질들의 도메인 구성도 동일하였다.
Tubulysins are a group of bioactive secondary metabolites from myxobacteria exhibiting strong anticancer activity against various cancer cell lines. In this study, we describe the identification of putative tubulysin biosynthetic gene clusters (tubA~tubF) in the genome sequences of two tubulysin-producing myxobacterial strains, Archangium gephyra MEHO_002 and MEHO_004. The inactivation of the putative tubulysin biosynthetic genes resulted in a tubulysin-production defect. The DNA sequences of the A. gephyra MEHO_002 and MEHO_004 tubulysin biosynthetic genes were 97% identical, and the amino acid sequences of the encoded proteins shared a similarity of 97-100%. The nucleotide sequences of the tubulysin biosynthetic gene clusters in MEHO_002 and MEHO_004 were 86% identical to that in Cystobacter sp. SBCb004 known as a tubulysin-producing myxobacterium, and the organization of the clusters was identical except for the lack of a tubZ gene in the clusters in MEHO_002 and MEHO_004. The amino acid sequences of the proteins encoded by each gene were 88-97% similar to those encoded by SBCb004, and the domain compositions of the proteins were also identical.
Myxococcus xanthus,
a myxobacterium, displays phase variation between yellow phase and tan phase. We found that deletion of the
encA
gene encoding encapsulin and the
encF
gene encoding a ...metalloprotease causes formation of tan colonies that never transform into yellow colonies. The
encA
and
encF
mutants were defective in the production of DK-xanthene and myxovirescin. They did not produce extracellular polysaccharides; hence, the cells did not aggregate in liquid and showed reduced swarming on agar plates. The mutants had defective sporulation, but were rescued extracellularly by wild type cells. All these traits indicate that the
encA
and
encF
mutants are likely to be tan-phase-locked, and encapsulin has a close relationship with phase variation in
M. xanthus.
The
encA
and
encF
genes are localized in the same gene cluster,
encBAEFG
(MXAN_3557~MXAN_3553). Unlike the
encA
and
encF
genes, deletion of other genes in the cluster did not show tan-phase-locked phenotype.
Here, Podospora leporina was isolated and cultured from Cypripedium guttatum Sw. (spotted lady’s slipper), which was designated as an endangered wildlife class 1 by the Ministry of Environment. ...Further, Podospora sp., which is found in Calanthe discolor Lindl. (Japanese hardy orchid) root is recorded as an endophytic fungus in Jeju Island, Korea. However, there is no existing record of Podospora spp. Thus, in this study, we analyzed the morphological characteristics and two molecular markers, internal transcribed spacer (ITS) and large ribosomal subunit (LSU), of P. leporina and compared these data with other relative species. Consequently, this endophytic fungal species was confirmed as an unrecorded species in Korea, so we presented cultural characteristics and microstructures, such as the conidia of P. leporina.
Myxococcus xanthus, a myxobacterium, displays phase variation between yellow phase and tan phase. We found that deletion of the encA gene encoding encapsulin and the encF gene encoding a ...metalloprotease causes formation of tan colonies that never transform into yellow colonies. The encA and encF mutants were defective in the production of DKxanthene and myxovirescin. They did not produce extracellular polysaccharides; hence, the cells did not aggregate in liquid and showed reduced swarming on agar plates. The mutants had defective sporulation, but were rescued extracellularly by wild type cells. All these traits indicate that the encA and encF mutants are likely to be tan-phase-locked, and encapsulin has a close relationship with phase variation in M. xanthus. The encA and encF genes are localized in the same gene cluster, encBAEFG (MXAN_3557~MXAN_3553).
Unlike the encA and encF genes, deletion of other genes in the cluster did not show tan-phase-locked phenotype. KCI Citation Count: 8
The whole genome sequence of the argyrin- and tubulysinproducing myxobacterium Archangium gephyra KYC5002 was analyzed. The genome of A. gephyra KYC5002 was assembled into a 13,249,988 bp circular ...genome with a G + C content of 68.8%, containing 10,298 protein-coding genes, 12 rRNA genes, and 95 tRNA genes. In the A. gephyra KYC5002 genome, 53 secondary metabolite biosynthetic gene clusters (BGCs) were detected in 46 regions; the total length of these genes was 6.81% of the total genome. The genome was predicted to contain BGCs for argyrins, carotenoids, DKxanthenes, gephyronic acid, geosmins, microviridins, myxochellins, and tubulysins. KCI Citation Count: 0
PDF
