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81.
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Kezuka Y Kitazaki K Itoh Y Watanabe J Takaha O Watanabe T Nishizawa Y Nonaka T 《Protein and peptide letters》2004,11(4):401-405
We report here on crystallization and preliminary X-ray analysis of plant class I chitinase from rice (OsChia1b). Similar single crystals of full-length OsChia1b were obtained under two independent conditions. The crystals grown under these conditions diffracted up to 2.1 and 2.5 angstroms resolution, respectively, at a synchrotron beamline, and were found to belong to the tetragonal space group P4(3)2(1)2. 相似文献
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Photosystem II (PSII) is a multisubunit chlorophyll–protein complex that drives electron transfer from water to plastoquinone using energy derived from light. In green plants, the native form of PSII is surrounded by the light-harvesting complex (LHCII complex) and thus it is called the PSII–LHCII supercomplex. Over the past several years, understanding of the structure, function, and assembly of PSII and LHCII complexes has increased considerably. The unicellular green alga Chlamydomonas reinhardtii has been an excellent model organism to study PSII and LHCII complexes, because this organism grows heterotrophically and photoautotrophically and it is amenable to biochemical, genetic, molecular biological and recombinant DNA methodology. Here, the genes encoding and regulating components of the C. reinhardtii PSII–LHCII supercomplex have been thoroughly catalogued: they include 15 chloroplast and 20 nuclear structural genes as well as 13 nuclear genes coding for regulatory factors. This review discusses these molecular genetic data and presents an overview of the structure, function and assembly of PSII and LHCII complexes. 相似文献
85.
Schizosaccharomyces pombe RanGAP homolog, SpRna1, is required for centromeric silencing and chromosome segregation 下载免费PDF全文
Kusano A Yoshioka T Nishijima H Nishitani H Nishimoto T 《Molecular biology of the cell》2004,15(11):4960-4970
We isolated 11 independent temperature-sensitive (ts) mutants of Schizosaccharomyces pombe RanGAP, SpRna1 that have several amino acid changes in the conserved domains of RanGAP. Resulting Sprna1ts showed a strong defect in mitotic chromosome segregation, but did not in nucleocytoplasmic transport and microtubule formation. In addition to Sprna1+ and Spksp1+, the clr4+ (histone H3-K9 methyltransferase), the S. pombe gene, SPAC25A8.01c, designated snf2SR+ (a member of the chromatin remodeling factors, Snf2 family with DNA-dependent ATPase activity), but not the spi1+ (S. pombe Ran homolog), rescued a lethality of Sprna1ts. Both Clr4 and Snf2 were reported to be involved in heterochromatin formation essential for building the centromeres. Consistently, Sprna1ts was defective in gene-silencing at the centromeres. But a silencing at the telomere, another heterochromatic region, was normal in all of Sprna1ts strains, indicating SpRna1 in general did not function for a heterochromatin formation. snf2SR+ rescued a centromeric silencing defect and Deltaclr4+ was synthetic lethal with Sprna1ts. Taken together, SpRna1 was suggested to function for constructing the centromeres, by cooperating with Clr4 and Snf2SR. Loss of SpRna1 activity, therefore, caused chromosome missegregation. 相似文献
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A study was made of cambial activity, the localization of storage starch around the cambium, and the localization and occurrence
of microtubules in cambial cells from dormancy to reactivation in locally heated (22–26 °C) stems of the evergreen conifer
Abies sachalinensis. Heating induced localized reactivation of the cambium in the heated portions of the stem. Erect ray cambial cells resumed
cell division 1 d prior to the reactivation of fusiform cambial cells and procumbent ray cambial cells. The re-initiation
of the division of fusiform cambial cells occurred first on the phloem side. During the heat treatment, the amount of storage
starch decreased in procumbent ray cambial cells and in the phloem parenchyma adjacent to the cambium but increased in fusiform
cambial cells. Preprophase bands of microtubules, spindle microtubules and phragmoplast microtubules were observed both in
erect ray cambial cells and in procumbent ray cambial cells. By contrast, no evidence of the presence of such preprophase
bands of microtubules was detected in fusiform cambial cells. The results suggest that the localized heating of stems of evergreen
conifers might provide a useful experimental model system for studies of the dynamics of cambial reactivation in intact trees.
Received: 25 May 2000 / Accepted: 12 July 2000 相似文献
88.
We describe a cis element that dramatically increases the expression levels of exogenous genes in baculovirus-infected insect cells. This 21 bp sequence element is derived from a 5' untranslated leader sequence of a lobster tropomyosin cDNA (L21). By using a transfer vector carrying L21, the expression levels of tropomyosin and luciferase were 20- and seven-fold higher with L21 than without L21, respectively. L21 has both the Kozak sequence and the A-rich sequence found in the polyhedrin leader sequence. We assume that both sequence elements are essential for the enhancement of protein expression in the baculovirus-based expression system. 相似文献
89.
Masumoto K Ueda T Nagata M Yamada Y Yoshida Y Hashimoto Y Imoto T 《Protein and peptide letters》2002,9(5):435-439
We investigated thermal stabilities of four proteins in the presence of four kinds of sugars to analyze the mechanism of stabilization of proteins by additives. These proteins were stabilized by the addition of sugars, and the degree of stabilization correlated to the partial molar isentropic compressibility of the sugar. 相似文献
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