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The heterotrimeric structure of kinesin-2 makes it a unique member of the kinesin superfamily; however, molecular details of the oligomer formation are largely unknown. Here we demonstrate that heterodimerization of the two distinct motor domains KLP11 and KLP20 of Caenorhabditis elegans kinesin-2 requires a dimerization seed of merely two heptads at the C terminus of the stalk. This heterodimeric seed is sufficient to promote dimerization along the entire length of the stalk, as shown by circular dichroism spectroscopy, Förster resonance energy transfer analysis, and electron microscopy. In addition to explaining the formation of the kinesin-2 stalk, the seed sequence identified here bears great potential for generating specific heterodimerization in other protein biochemical applications. 相似文献
65.
Ante Žuljević Thierry Thibaut Marija Despalatović Jean-Michel Cottalorda Vedran Nikolić Ivan Cvitković Boris Antolić 《Biological invasions》2011,13(10):2303-2308
Here we present the first observation of the impact of the invasive Caulerpa racemosa var. cylindracea on native photophilic sponge species in the Adriatic Sea, with special focus on Sarcotragus spinosulus. Caulerpa racemosa var. cylindracea is able to completely overgrow the sponge, developing an exceptionally thick canopy with a maximum measured density of 1,887 m
of stolons m−2 and 40,561 fronds m−2. Necrosis of the sponge surface was significantly correlated with the algal dry biomass, frond number and stolon length.
Dense algal canopy, penetration of the algal stolon and rhizoids into the sponge oscula and covering of the ostiae probably
diminishes the seawater circulation through the sponge and consequently results in its smothering and even death. We suggest
that chemotropism is the reason why C. racemosa penetrates the sponge oscula and establishes such dense canopy on the sponge. 相似文献
66.
Petrovic S Leskovac A Kotur-Stevuljevic J Joksic J Guc-Scekic M Vujic D Joksic G 《Biological chemistry》2011,392(7):625-632
Abstract Fanconi anemia (FA) is a rare cancer-prone genetic disorder characterized by progressive bone marrow failure, chromosomal instability and redox abnormalities. There is much biochemical and genetic data, which strongly suggest that FA cells experience increased oxidative stress. The present study was designed to elucidate if differences in oxidant state exist between control, idiopathic bone marrow failure (idBMF) and FA cells, and to analyze oxidant state of cells in FA heterozygous carriers as well. The results of the present study confirm an in vivo prooxidant state of FA cells and clearly indicate that FA patients can be distinguished from idBMF patients based on the oxidant state of cells. Female carriers of FA mutation also exhibited hallmarks of an in vivo prooxidant state behaving in a similar manner as FA patients. On the other hand, the oxidant state of cells in FA male carriers and idBMF families failed to show any significant difference vs. controls. We demonstrate that the altered oxidant state influences susceptibility of cells to apoptosis in both FA patients and female carriers. The results highlight the need for further research of the possible role of mitochondrial inheritance in the pathogenesis of FA. 相似文献
67.
Senka Vidović Zoran Zeković Ibrahim Mujić Žika Lepojević Marija Radojković Jelena Živković 《Central European Journal of Biology》2011,6(4):575-582
Daedaleopsis confragosa belong to a large and remarkable group of mushrooms called polypores. This type of mushroom could be easily said to be quite
unexplored and unused when it comes to its antioxidant properties. Thus, in order to evaluate its antioxidant activity, the
investigation had to include the total phenolics and flavonoide content, the content of Selenium, the content of Zinc, the
scavenging capacity on DPPH· and OH· radicals, reducing power and capacity to remove lipid peroxidation. The investigated mushroom extract contained 54.17 mg
GAE/g of total phenols and 48.46 mg CE/g of total flavonoides. Zinc and Selenium were detected and quantified by using inductively
coupled plasma mass spectroscopy. The scavenging activity of the radicals was found to exhibit 50% of the inhibition value
(IC50 value) at the extract concentration of 0.015±0.007 mg/ml for the investigated D. confragosa extract. By using electron paramagnetic resonant spectroscopy it was found that the investigated extract does not have a
significant role in the prevention of lipid peroxidation. It was effective in scavenging on ·OH radical, RI was 56±2%. 相似文献
68.
Marija Gimbutas 《American anthropologist》1952,54(4):602-611
69.
Marta Narczyk Marta Ilona Wojty Ivana Le
i Aler Biserka
ini Marija Lui Elbieta Katarzyna Jagusztyn-Krynicka Zoran tefani Agnieszka Bzowska 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):1083
Helicobacter pylori represents a global health threat with around 50% of the world population infected. Due to the increasing number of antibiotic-resistant strains, new strategies for eradication of H. pylori are needed. In this study, we suggest purine nucleoside phosphorylase (PNP) as a possible new drug target, by characterising its interactions with 2- and/or 6-substituted purines as well as the effect of these compounds on bacterial growth. Inhibition constants are in the micromolar range, the lowest being that of 6-benzylthio-2-chloropurine. This compound also inhibits H. pylori 26695 growth at the lowest concentration. X-ray structures of the complexes of PNP with the investigated compounds allowed the identification of interactions of inhibitors in the enzyme’s base-binding site and the suggestion of structures that could bind to the enzyme more tightly. Our findings prove the potential of PNP inhibitors in the design of drugs against H. pylori. 相似文献
70.
Tina Paradzik Nives Ivic Zelimira Filic Babu A. Manjasetty Paul Herron Marija Luic Dusica Vujaklija 《Nucleic acids research》2013,41(6):3659-3672
The linear chromosome of Streptomyces coelicolor contains two paralogous ssb genes, ssbA and ssbB. Following mutational analysis, we concluded that ssbA is essential, whereas ssbB plays a key role in chromosome segregation during sporulation. In the ssbB mutant, ∼30% of spores lacked DNA. The two ssb genes were expressed differently; in minimal medium, gene expression was prolonged for both genes and significantly upregulated for ssbB. The ssbA gene is transcribed as part of a polycistronic mRNA from two initiation sites, 163 bp and 75 bp upstream of the rpsF translational start codon. The ssbB gene is transcribed as a monocistronic mRNA, from an unusual promoter region, 73 bp upstream of the AUG codon. Distinctive DNA-binding affinities of single-stranded DNA-binding proteins monitored by tryptophan fluorescent quenching and electrophoretic mobility shift were observed. The crystal structure of SsbB at 1.7 Å resolution revealed a common OB-fold, lack of the clamp-like structure conserved in SsbA and previously unpublished S-S bridges between the A/B and C/D subunits. This is the first report of the determination of paralogous single-stranded DNA-binding protein structures from the same organism. Phylogenetic analysis revealed frequent duplication of ssb genes in Actinobacteria, whereas their strong retention suggests that they are involved in important cellular functions. 相似文献