• Journal of Microbiology
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• 제35권4호
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• pp.323-326
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• 1997

Toxin protein from Ustilago maydis virus SH14 isolated in Korea was purified using ethanol precipitation, cation exchange, gel filtration and anion exchange chromatography. The molecular weight of the purified protein was estimated to be 8.3 kDa by SDS-PAGE analysis. The Nterminal sequence of the protein is L-G-I-N-C(K)-R-G-S-S-Q--C(K)-G-L-S-G which is highly homologous with that of P4 toxin, but the amino acid composition and electrophoretic mobility in a native PAGE of the toxin protein were totally different from those of P4 toxin respectively. The SH14 toxin was shown to have immunological cross-reactivity about 50% with P4 toxin when examined by Western hybridization.

• 미생물학회지
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• 제31권3호
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• pp.184-188
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• 1993

Novel Ustilagomaydis strains, designated as SH1 to 14 containing new types of ds RNA segments, are identified from corn smut in Korea. Among 14 isolates, 7 isolates appear to posses virus particles and the other isolates may contain dsRNA as a plasmid form. The pattern of dsRNA is highly diverse form a typical P-type containing one or more of H, M, and L dsRNAs to the one containing one or move M dsRNAs. It is likely that the strains containing H dsRNA posses virus particles which were confirmed by sucrose density gradient followed with different range of specificity and the activity of the strain (SH14) is stronger than A4 toxin. The sensitivity of 14 isolates is also very diverse and two strains (SH10, SH11) appear tobe universal sensitve strains against 5 tested toxin samples.

• Journal of Microbiology
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• 제33권2호
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• pp.154-159
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• 1995

SH-14, a novel killer strain of Ustilago maydis was isolated in Korea. It has been reported in other papers that the toxin specificity and double-stranded RNA pattern of SH-14 strain were different from other laboratory strains. In this paper, we analyzed the biochemical characteristics of U. maydis SH-14 virus. Three distinctive peaks were isolated from CsCl density gradient, designated as top (T), intermediate (I) and bottom (B) components. We found that the densities of each components, 1.285, 1.408 g/cm$\^$3/, respectively, are very similar to those of other strains. As previously reported by the analysis of dsRNA in each component, the dsRNA segments are separately encapsidated. Capsid protein of SH-14 virus consists of two proteins about 70 Kd shown by SDS-PAGE analysis. Electron microscopic examination of the virus particles revealed that UmV particles are very similar in size and morphology to all isolates as well as all lab-strains. In order to test immunological cross reactivity of UmV, werstern bolt analysis was carriedout with antiserum against A8 virus. All capsid protein had positive reaction against A8 antibody which indicated that UmV are immunologically cross-reactive with all isolates from Korea. The results presented in this paper may show that UmV isolated from SH-14 strain has very similar biochemical characteristics to those of other UmV. However, the difference in the toxin specificity and the molecular weight of toxin protein from the SH-14 strain has us to conclude that U. maydis SH-14 strain is a new killer type.

• 미생물학회지
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• 제33권2호
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• pp.105-110
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• 1997

한국에서 분리한 U. maydis에서 바이러스 혹은 dsRNA를 가지고 있는 A series와 SH series를 조합하여 옥수수에서 인위적으로 mating시켜 A45, A23, A211, A310, SH614, SH24의 6개 교배형 균주를 분리하였다. 새로운 교배형 균주에서 바이러스 dsRNA를 비교 분석하여 본 결과, mating전 양친형 균주에서 보이고 있는 H, M, L strand의 dsRNA 양상을 모두 가지고 있고 균주간 특별한 molecular exclusion 현상은 보이지 않았다. 교배형 6개으 균주에서 바이러스를 분리하였다. 분리된 바이러스로부터 dsRNA를 분석한 결과 균주간 mating시 dsRNA 재조합을 통한 새로운 encapsidation은 발생하지 않는다는 것을 확인하였다. Toxin test 결과, SH614는 SH9, SH10, SH11 균주에 대해서, A310과 SH24의 2종은 SH11 균주에 대해 특이적 성장억제 현상을 보였다. 이는 mating에 따른 dsRNA의 재조합이 toxin gene의 발현에 영향을 미치지 않는다는 것을 시사한다.

• 미생물학회지
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• 제30권3호
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• pp.177-180
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• 1992

Among 120 U. maydis strains isolated in Korea 14 different strains containing specific viral dsRNA segments were analyzed for the distribution of dsRNA and the production of toxin protein. Several distinctive dsRNA patterns were identified, 9 cases of P type with typical H, M and L ds RNA and one case of non-P-type, the frequency of a specific isolate was decreased with increasing number of dsRNA segments. The presence of dsRNA had no effect on the cultural or morphological phenotype of the host. Two isolates containing P type dsRNA segments appeared to produce toxin protein (killer strains) which inhibited the growth of 4 isolates (sensitive strain) with different susceptibility. Two killer strains contain unique M dsRNA segment which may code for toxin protein. However, the presence of toxin-sensitive strains among dsRNA-free isolates was similar to that of ds RNA containing strains.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1994년도 한국생물과학협회 학술발표대회
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• pp.153.2-153
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• 1994

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.225.1-225
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• 1999

No Abstract, See Full Text