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1.
Yi-Hua Wu Chia-Pei Chang Chin-I Chien Yi-Kuan Tseng Chien-Chia Wang 《Molecular and cellular biology》2013,33(17):3515-3523
The yeast Saccharomyces cerevisiae possesses two distinct glycyl-tRNA synthetase (GlyRS) genes: GRS1 and GRS2. GRS1 is dually functional, encoding both cytoplasmic and mitochondrial activities, while GRS2 is dysfunctional and not required for growth. The protein products of these two genes, GlyRS1 and GlyRS2, are much alike but are distinguished by an insertion peptide of GlyRS1, which is absent from GlyRS2 and other eukaryotic homologues. We show that deletion or mutation of the insertion peptide modestly impaired the enzyme''s catalytic efficiency in vitro (with a 2- to 3-fold increase in Km and a 5- to 8-fold decrease in kcat). Consistently, GRS2 can be conveniently converted to a functional gene via codon optimization, and the insertion peptide is dispensable for protein stability and the rescue activity of GRS1 at 30°C in vivo. A phylogenetic analysis further showed that GRS1 and GRS2 are paralogues that arose from a gene duplication event relatively recently, with GRS1 being the predecessor. These results indicate that GlyRS2 is an active enzyme essentially resembling the insertion peptide-deleted form of GlyRS1. Our study suggests that the insertion peptide represents a novel auxiliary domain, which facilitates both productive docking and catalysis of cognate tRNAs. 相似文献
2.
Ming Pei You Brandon Lancaster Krishnapillai Sivasithamparam Martin John Barbetti 《Plant and Soil》2008,302(1-2):203-211
In Australia, in the past, pasture legumes were rotated mainly with cereals, but increasingly these rotations now involve
pasture legumes with a wider range of crops, including legumes. This increasing frequency of the leguminous host in the rotation
system may be associated with increased root rots in legumes in the current pasture-crop rotations. The primary aim of this
study was to see whether the pathogenicity on pasture legumes of strains of Rhizoctonia solani sourced from lupins and cereals (common crops in rotation with pastures) is associated with increased incidence of root rots
in pasture legumes in the disease conducive sandy soils of the Mediterranean regions of southern Australia. The second aim
was to determine sources of resistance among newly introduced pasture legumes to R. solani strains originating from rotational crops as this would reduce the impact of disease in the pasture phase. Fifteen pasture
legume genotypes were assessed for their resistance/susceptibility to five different zymogram groups (ZG) of the root rot
pathogen R. solani under glasshouse conditions. Of the R. solani groups tested, ZG1–5 and ZG1–4 (both known to be pathogenic on cereals and legumes) overall, caused the most severe root
disease across the genotypes tested, significantly more than ZG6 (known to be pathogenic on legumes), in turn significantly
>ZG4 (known to be pathogenic on legumes) which in turn was >ZG11 (known to be pathogenic on legumes including tropical species).
Overall, Ornithopus sativus Brot. cvs Cadiz and Margurita, Trifolium michelianum Savi. cvs Paradana and Frontier and T. purpureum Loisel. cv. Electro showed a significant level of resistance to root rot caused by R. solani ZG11 (root disease scores ≤1.2 on a 1–3 scale where 3 = maximum disease severity) while O. sativus cvs Cadiz and Erica showed a significant level of resistance to root rot caused by R. solani ZG4 (scores ≤1.2). O. compressus L. cvs Charano and Frontier, O. sativus cv. Erica, and T. purpureum cv. Electro showed some useful resistance to root rot caused by R. solani ZG6 (scores ≤1.8). This is the first time that cvs Cadiz, Electro, Frontier, Margurita and Paradana have been recognised
for their levels of resistance to root rot caused by R. solani ZG11; and similarly for cvs Cadiz and Erica against ZG4; and for cvs Charano, Erica, and Electro against ZG6. These genotypes
with resistance may also serve as useful sources of resistance in pasture legume breeding programs and also could potentially
be exploited directly into areas where other rotation crops are affected by these R. solani strains. None of the tested genotypes showed useful resistance to R. solani ZG1–4 (scores ≥2.0) or ZG1–5 (scores ≥2.5). This study demonstrates the relative potential of the various R. solani ZG strains, and particularly ZG1–4, ZG1–5, ZG4 and ZG6 to attack legume pastures and pose a significant threat to non-pasture
crop species susceptible to these strains grown in rotation with these pasture legumes. Significantly, the cross-pathogenicity
of these strains could result in the continuous build-up of inoculum of these strains that may seriously affect the productivity
eventually of legumes in all rotations. In particular, when choosing pasture legumes as rotation crops, caution needs to be
exercised so that the cultivars deployed are those with the best resistance to the R. solani ZGs most likely to be prevalent at the location. 相似文献
3.
4.
Hailong Jin Congran Li Ding Li Ming Cai Zhouli Li Shuang Wang Xin Hong Bingyi Shi 《Cell biochemistry and biophysics》2013,67(3):1067-1074
Immunotoxins with selective cytotoxicity are frequently used as therapeutic immunosuppressive agents in solid-organ transplantation because of their efficiency and high specificity. In this study, we present a new recombinant immunotoxin termed anti-CTLA-4-scFv–melittin prepared from Escherichia coli aimed at clearing activated T cells at the same time avoiding all-round decline in systematic immunity. This fusion protein is composed of anti-CTLA-4-scFv unit and melittin analog unit with properties of low immunogenicity and selective cytotoxicity to CTLA-4-positive T cells. In preliminary biological activity assays, our results confirmed the feasibility of activated T cell clearance strategy and there were significant differences in cell survival rates between CTLA-4-positive group and control group at all experimental concentrations of the immunotoxin. The selective cytotoxicity, low immunogenicity, and low production cost make it an attractive alternate to traditional immunosuppressants. 相似文献
5.
C. S. Lin M. C. Tseng P. I. Hong W. C. Chang 《In vitro cellular & developmental biology. Plant》2006,42(4):331-335
Summary Inflorescence proliferation is a plant tissue culture technique that, can be used to obtain in vitro inflorescences year-round without the intervening development of vegetative organs. In this study, we used albino mutant
inflorescences of Dendrocalamus latiflorus as the original explant material to investigate, the effect of plant growth regulators on long-term inflorescence proliferation.
The albino inflorescences proliferated on solidified Murashige and Skoog (MS) basal medium supplemented with thidiazuron (TDZ),
and the optimal concentration for successful long-term inflorescence proliferation was 0.45 μM TDZ. A combination of α-naphthaleneacetic acid (NAA) with 0.45 μM TDZ inhibited the inflorescence proliferation. Inflorescences cultured on a TDZ-free medium supplemented with 26.82 μM NAA rooted in 21 d, vegetative shoots formed by 42 d and, in one case, flowering occurred after 63 d. The auxins 2,4-dichlorophenoxyacetic
acid (2,4-D, 4.52 μM) and pieloram (4.14 μM) induced shoot formation. The protocol described can be used to produce large numbers of mutant inflorescences within a relatively
short period of time. 相似文献
6.
R E Loomis C C Tseng E J Bergey M J Levine 《International journal of peptide and protein research》1988,32(2):130-140
The amino acid sequence G(1)-P(2)-P(3)-P(4)-H(5)-P(6)-G(7)-K(8)-P(9) occurs twice in the proline-rich glycoprotein (PRG) found in human parotid saliva. As part of our efforts to elucidate the structure-function relationships of PRG, this nonapeptide sequence (PRG9) was synthesized for the purpose of conformational analyses by high-resolution proton n.m.r. spectroscopy and computer-modeling. The empirical n.m.r. spectrum differed from the simulated spectrum in that the overall chemical shift locations were displaced from their random coil positions and the five proline residues had non-degenerate C alpha H alpha protons. Other n.m.r. data indicated that no intramolecular hydrogen-bonding was present in the PRG. In conjunction with X-ray crystallographic data on a triproline-containing model compound (Kartha, g., Ashida, T. & Kakudo, M. (1974) Acta Cryst. B30, 1861-1866), four energy-minimized PRG9 structures were obtained. Two of the structures were energetically unfavorable, while the other two conformations were reasonable. The two most likely structures gave all prolines an S-type ring pucker, the P(2)-P(3)-P(4) sequence as a poly-L-proline II helix, the H(5) phi = -90.3 degrees, P(6) and P(9) with trans peptide bond orientation, G(7) in an extended state, and the K(8) phi = -93.2 degrees or -146.8 degrees for structures #1 and #2, respectively. 相似文献
7.
Abdulrazak Osama Han Ming Gan Cindy Shuan Ju Teh Kien-Pong Yap Kwai-Lin Thong 《Journal of bacteriology》2012,194(24):6933
The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na+-driven multidrug efflux pump-coding gene in the genome of Vibrio cholerae with the highest similarity to VMA_001754 of Vibrio mimicus VMA223. 相似文献
8.
The complete nucleotide sequence of the mitochondrial (mt) genome was determined for specimens of the coral species Montipora
cactus (Bernard 1897) and Anacropora
matthai (Pillai 1973), representing two morphologically distinct genera of the family Acroporidae. These sequences were compared
with the published mt genome sequence for the confamilial species, Acropora tenuis (Dana 1846). The size of the mt genome was 17,887 bp and 17,888 bp for M. cactus and A. matthai. Gene content and organization was found to be very similar among the three Acroporidae mt genomes with a group I intron
occurring in the NADH dehyrogenase 5 (nad5) gene. The intergenic regions were also similar in length among the three corals. The control region located between the
small ribosomal RNA (ms) and the cytochrome oxidase 3 (cox3) gene was significantly smaller in M. cactus and A. matthai (both 627 bp) than in A. tenuis (1086 bp). Only one set of repeated sequences was identified at the 3′-end of the control regions in M. cactus and A. matthai. A lack of the abundant repetitive elements which have been reported for A. tenuis, accounts for the relatively short control regions in M. cactus and A. matthai. Pairwise distances and relative rate analyses of 13 protein coding genes, the group I intron and the largest intergenic
region, igr3, revealed significant differences in the rate of molecular evolution of the mt genome among the three species, with an extremely
slow rate being seen between Montipora and Anacropora. It is concluded that rapid mt genome evolution is taking place in genus Acropora relative to the confamilial genera Montipora and Anacropora although all are within the relatively slow range thought to be typical of Anthozoa. 相似文献
9.
10.
The chemiluminescence (CL) of bis(2,4,6‐trichlorophyenyl) oxalate with hydrogen peroxide in the present of cationic surfactant and gold nanoparticles was studied. The CL emission was obviously enhanced in the presence of surfactant at a suitable concentration, with a synergetic catalysis effect exhibited. Different sizes of gold nanoparticles (15 and 50 nm) showed different effects on CL intensity. Mechanisms of the CL reaction and sensitization effect are discussed. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献