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911.
Y. Bao H. Xie J. Shan R. Jiang Y. Zhang L. Guo R. Zhang Y. Li 《Journal of applied microbiology》2009,106(4):1140-1146
Aims: Ebosin, a novel exopolysaccharide (EPS) produced by Streptomyces sp. 139 has antagonistic activity for interleukin-1 receptor (IL-1R) in vitro and remarkable anti-rheumatic arthritis activity in vivo. Ebosin biosynthesis gene ( ste ) cluster has been identified in our laboratory. This paper reports our effort to characterize the function of ste11 gene.
Methods and Results: After the ste11 gene was cloned and expressed in Escherichia coli BL21, the recombinant Ste11 was purified and found capable of catalyzing NAD+ and l -threonine to NADH and 2-amino-3-ketobutyrate, hence identified as a threonine dehydrogenase (TDH). To investigate its function in the biosynthesis of Ebosin, the ste11 gene was knocked out with a double crossover via homologous recombination. The monosaccharide composition of EPS produced by the mutant strain (EPS-m) was altered from that of Ebosin. The analysis of IL-1R antagonist activity for EPSs showed that the bioactivity of EPS-m was lower than Ebosin.
Conclusions: ste11 gene encoding a TDH may function as a modifier gene of Ebosin during its biosynthesis.
Significance and Impact of the Study: TDH encoded by ste11 is functional in Ebosin biosynthesis. It is the first characterized TDH in Streptomyces . 相似文献
Methods and Results: After the ste11 gene was cloned and expressed in Escherichia coli BL21, the recombinant Ste11 was purified and found capable of catalyzing NAD
Conclusions: ste11 gene encoding a TDH may function as a modifier gene of Ebosin during its biosynthesis.
Significance and Impact of the Study: TDH encoded by ste11 is functional in Ebosin biosynthesis. It is the first characterized TDH in Streptomyces . 相似文献
912.
Wenzhe Wang Jianwei Pan Ke Zheng Honghong Shao Hongwu Bian Junhui Wang 《Biochemical and biophysical research communications》2009,383(1):141-145
Our previous data showed that apoptotic suppressors inhibit aluminum (Al)-induced programmed cell death (PCD) and promote Al tolerance in yeast cells, however, very little is known about the underlying mechanisms, especially in plants. Here, we show that the Caenorhabditis elegans apoptotic suppressor Ced-9, a Bcl-2 homologue, inhibited both the Al-induced PCD and Al-induced activity of caspase-like vacuolar processing enzyme (VPE), a crucial executioner of PCD, in tobacco. Furthermore, we show that Ced-9 significantly alleviated Al inhibition of root elongation, decreased Al accumulation in the root tip and greatly inhibited Al-induced gene expression in early response to Al, leading to enhancing the tolerance of tobacco plants to Al toxicity. Our data suggest that Ced-9 promotes Al tolerance in plants via inhibition of Al-induced PCD, indicating that conserved negative regulators of PCD are involved in integrated regulation of cell survival and Al-induced PCD by an unidentified mechanism. 相似文献
913.
Dina Ahram T. Shawn Sato Abdulghani Kohilan Marwan Tayeh Shan Chen Suzanne Leal Mahmoud Al-Salem Hatem El-Shanti 《American journal of human genetics》2009,84(2):274-278
Ectopia lentis is a genetically heterogeneous condition that is characterized by the subluxation of the lens resulting from the disruption of the zonular fibers. Patients with ectopia lentis commonly present with a marked loss in visual acuity in addition to a number of possibly accompanying ocular complications including cataract, myopia, and retinal detachment. We here describe an isolated form of ectopia lentis in a large inbred family that shows autosomal-recessive inheritance. We map the ectopia lentis locus in this family to the pericentromeric region on chromosome 1 (1p13.2-q21.1). The linkage region contains well more than 60 genes. Mutation screening of four candidate genes revealed a homozygous nonsense mutation in exon 11 of ADAMTSL4 (p.Y595X; c.1785T→G) in all affected individuals that is absent in 380 control chromosomes. The mutation would result in a truncated protein of half the original length, if the mRNA escapes nonsense-mediated decay. We conclude that mutations in ADAMTSL4 are responsible for autosomal-recessive simple ectopia lentis and that ADAMTS-like4 plays a role in the development and/or integrity of the zonular fibers. 相似文献
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寄生隐丛赤壳菌Cryphonectria parasitica致病毒素Cp-I的分离纯化和结构分析 总被引:1,自引:0,他引:1
寄生隐丛赤壳菌Cryphonectria parasitica菌株经液体培养,石油醚萃取其发酵液获得对板栗带叶嫩枝具有致萎活性的粗提物,以氯仿:石油醚:甲醇(6:2:2)作洗脱剂,粗提物经硅胶色谱分离,共得到3组纯组份,其中第1组份(Cp-I)对板栗幼苗致萎活性较高.质谱、核磁共振和红外光谱测定表明Cp-I分子量为278,化学式为C<,16>H<,22>O<,4>. 相似文献
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