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51.
表观遗传学对于微生物的生命进程起着重要作用。由限制-修饰系统调控的DNA修饰参与微生物的免疫防御系统,无限制-修饰系统调控的DNA修饰通过调控基因表达影响表型。然而,表观遗传信息还没有被常规地作为DNA信息收集分析。基于对DNA合成反应的动力学分析,单分子实时测序技术可以在获得基本序列数据的同时实现对被修饰核苷酸的检测。这个技术为微生物中已知DNA修饰的研究提供了新的平台,也为新型DNA修饰的发现做好准备。本文综述了单分子实时测序技术及其在微生物表观遗传学中的应用。 相似文献
52.
从海南热带植物园土壤样品中分离获得一株具有较强杀线虫活性的放线菌菌株DA09202,通过形态特征、生理生化特征、16SrDNA序列测定及其系统发育分析,初步鉴定为金色链霉菌。菌株DA09202发酵液采用溶媒萃取、硅胶柱层析、Sephadex LH-20凝胶过滤和制备薄层板层析,从中分离得到杀线虫活性化合物A23-1和A46-2。化合物A23-1经光谱和波谱分析(UV、1H-NMR、13C-NMR、DEPT、1H-1HCOSY、HMBC、HSQC)以及文献对照,鉴定为4′,7-二羟基异黄酮,化合物A46-2的结构正在鉴定中。 相似文献
53.
Mortalin was over expressed in tumor cells and bind to p53 protein. This interaction was suggested to promote sequestration of p53 in the cytoplasm, thereby inhibiting its nuclear activity. The p53 is a tumor suppressor that is essential for the prevention of cancer development and loss of p53 function is one of the early events in immortalization of human cells. Therefore, abrogation p53-mortalin interaction using small molecule is guaranteed stop cancer cell grow. However study interaction of p53-mortalin, and its inhibition using small molecule is still challenging because specific site of mortalin that bind to p53, vice versa, is still debatable. This study has aims to analyze the p53-binding site of mortalin using molecular docking and to screen drug-like compounds that have potential as inhibitors of p53-mortalin interaction using virtual screening. The result showed that the lowest energy binding of p53-mortalin complex is -31.89 kcal/mol, and p53 protein bind to substrate binding domain of mortalin (THR433; VAL435; LEU436; LEU437; PRO442; ILE558; LYS555). Furthermore, the p53-binding domain of mortalin was used as receptor to screen 9000 drug-like compounds from ZINC database using molecular docking program Auto Dock Vina in PyRx 0.8 (Virtual Screening Tools). Here, we have identified three drug-like compounds that are ZINC01019934, ZINC00624418 and ZINC00664532 adequate to interrupt stability of p53-mortalin complex that warrant for anticancer agent. 相似文献
54.
Trans-imidazolium (bis imidazole) tetrachloro ruthenate (RuIm) and trans-indazolium (bis indazole) tetrachloro ruthenate (RuInd) are ruthenium coordination complexes, which were first synthesized and exploited for their anticancer activity. These molecules constitute two of the few most effective anticancer ruthenium compounds. The clinical use of these compounds however was hindered due to toxic side effects on the human body. Our present study on topoisomerase II poisoning by these compounds shows that they effectively poison the activity of topoisomerase II by forming a ternary cleavage complex of DNA, drug and topoisomerase II. The thymidine incorporation assays show that the inhibition of cancer cell proliferation correlates with topoisomerase II poisoning. The present study on topoisomerase II poisoning by these two compounds opens a new avenue for renewing further research on these compounds. This is because they could be effective lead candidates for the development of more potent and less toxic ruthenium containing topoisomerase II poisons. Specificity of action on this molecular target may reduce the toxic effects of these ruthenium-containing molecules and thus improve their therapeutic index. 相似文献
55.
56.
Akihiko Nishikimi Mutsuko Kukimoto-Niino Shigeyuki Yokoyama Yoshinori Fukui 《Experimental cell research》2013
DOCK proteins constitute a family of evolutionarily conserved guanine nucleotide exchange factors (GEFs) for Rho family of GTPases. Although DOCK family proteins do not contain the Dbl homology domain typically found in GEFs, they mediate the GTP–GDP exchange reaction through DHR-2 domain. Accumulating evidence indicates that the DOCK proteins act as major GEFs in varied biological settings. For example, DOCK2, which is predominantly expressed in hematopoietic cells, regulates migration and activation of leukocytes through Rac activation. On the other hand, it was recently reported that mutations of DOCK8, another member of the DOCK family proteins, cause a combined immunodeficiency syndrome in humans. This article reviews the structure, functions and signaling of DOCK2 and DOCK8, especially focusing on their roles in immune responses. 相似文献
57.
Riboprinting was used to determine the relationships among strains belonging to 15 species of the genusKluyveromyces. The small subunit ribosomal RNA gene (SSU rDNA) was amplified using the Polymerase Chain Reaction (PCR) and subjected to a battery of nine restriction enzymes. Similarity coefficients between strains were calculated based on shared and unique restriction fragments. Cluster analysis revealed three major groups that generally correlated with previously reported relationships based on other molecular data. Variations in SSU rDNA restriction fragments may be used for differentiation of theKluyveromyces strains included in this study.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged. 相似文献
58.
Jacob L. Jordan Joseph W. Arndt Karl Hanf Guohui Li Janine Hall Stephen Demarest Flora Huang Xiufeng Wu Brian Miller Scott Glaser Erik J. Fernandez Deping Wang Alexey Lugovskoy 《Proteins》2009,77(4):832-841
Bispecific immunoglobulin‐like antibodies capable of engaging multiple antigens represent a promising new class of therapeutic agents. Engineering of these molecules requires optimization of the molecular properties of one of the domain components. Here, we present a detailed crystallographic and computational characterization of the stabilization patterns in the lymphotoxin‐beta receptor (LTβR) binding Fv domain of an anti‐LTβR/anti‐TNF‐related apoptosis inducing ligand receptor‐2 (TRAIL‐R2) bispecific immunoglobulin‐like antibody. We further describe a new hierarchical structure‐guided approach toward engineering of antibody‐like molecules to enhance their thermal and chemical stability. Proteins 2009. © 2009 Wiley‐Liss, Inc. 相似文献
59.
Tsukamoto Y Taira E Kajimura K Yamate J Kotani T Amin H Kohama K Sakuma S Miki N Sasaki F 《Experimental cell research》1999,247(2):329-338
Gicerin is a novel cell adhesion molecule in the immunoglobulin superfamily and has both homophilic adhesion and heterophilic adhesive activity to neurite outgrowth factor (NOF), an extracellular matrix protein in the laminin family. We investigated the possible involvement of gicerin in oviductal development, regeneration, and metastasis of oviductal adenocarcinomas of the chicken. In the oviductal epithelium, gicerin was expressed strongly during development, disappeared after maturation, and reappeared during regeneration. NOF was constitutively expressed in the basement membrane of the epithelium. These molecules were expressed strongly in oviductal adenocarcinomas in both primary and metastatic lesions in the mesentery. An anti-gicerin antibody inhibited the attachment of adenocarcinoma cells to the mesentery in vitro. Many cells migrated from adenocarcinoma tissues on NOF, which were inhibited by an anti-gicerin antibody. These results suggest that gicerin might play a role in oviductal development and regeneration and also in the metastasis of adenocarcinomas. 相似文献
60.
HE Xiaolin LIU Xinqi ZENG Zonghao LI Hongmin WANG Miao ZHANG Ying WANG Dacheng 《中国科学C辑(英文版)》2000,43(1):39-46
BmK M4 is a neutral neurotoxin in the BmK toxin series.It is medially toxic and belongs to group III α-toxins.The purified sample was crystallized in rhombic space group P61.Using an X-ray diffraction technique,the crystal structure of BmK M4 was revealed by molecular replacement at 0.20 nm resolution.The model was refined.The final crystallographic R factor was 0.142 and the free R factor was 0.173.The root mean square deviation is 0.001 5 nm for the bond length and 1.753°for the bond angles.64 water molecules were added to the asymmetric unit.The refined structure showed an unusual non-prolyl cis peptide bond at residue 10.The structure was compared with group II α-toxin BmK M8 (an acidic,weak toxin).The potential structural implications of the cis peptide bond were discussed. 相似文献