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991.
G protein-coupled receptors (GPCRs) are transmembrane proteins, which transduce signals from extracellular ligands to intracellular
G protein. Automatic classification of GPCRs can provide important information for the development of novel drugs in pharmaceutical
industry. In this paper, we propose an evolutionary approach, GPCR-MPredictor, which combines individual classifiers for predicting
GPCRs. GPCR-MPredictor is a web predictor that can efficiently predict GPCRs at five levels. The first level determines whether
a protein sequence is a GPCR or a non-GPCR. If the predicted sequence is a GPCR, then it is further classified into family,
subfamily, sub-subfamily, and subtype levels. In this work, our aim is to analyze the discriminative power of different feature
extraction and classification strategies in case of GPCRs prediction and then to use an evolutionary ensemble approach for
enhanced prediction performance. Features are extracted using amino acid composition, pseudo amino acid composition, and dipeptide
composition of protein sequences. Different classification approaches, such as k-nearest neighbor (KNN), support vector machine (SVM), probabilistic neural networks (PNN), J48, Adaboost, and Naives Bayes, have been used to classify GPCRs. The proposed hierarchical GA-based ensemble classifier exploits
the prediction results of SVM, KNN, PNN, and J48 at each level. The GA-based ensemble yields an accuracy of 99.75, 92.45, 87.80, 83.57, and 96.17% at the five levels, on
the first dataset. We further perform predictions on a dataset consisting of 8,000 GPCRs at the family, subfamily, and sub-subfamily
level, and on two other datasets of 365 and 167 GPCRs at the second and fourth levels, respectively. In comparison with the
existing methods, the results demonstrate the effectiveness of our proposed GPCR-MPredictor in classifying GPCRs families.
It is accessible at . 相似文献
992.
993.
Goang-Won Cho Seung Min Shin Hyun Kee Kim Seon-Ah Ha Sanghee Kim Joo-Hee Yoon Soo Young Hur Tae Eung Kim Jin Woo Kim 《BMC cell biology》2007,8(1):50
Background
The Human cervical cancer oncogene (HCCR-1) has been isolated as a human oncoprotein, and has shown strong tumorigenic features. Its potential role in tumorigenesis may result from a negative regulation of the p53 tumor suppressor gene. 相似文献994.
995.
Nam Jin Noh Yowhan Son Rae Hyun Kim Kyung Won Seo Jin Woo Koo In Hyeop Park Young Jin Lee Kyeong Hak Lee Yeong Mo Son 《Journal of Plant Biology》2007,50(4):461-466
Above- and belowground biomass and nitrogen (N) and phosphorus (P) distribution within threeQuercus acutissima stands were investigated in central Korea. The average age (year) and diameter at breast height (DBH, cm) were 10.8 and 7.9
for Stand 1, 38.2 and 17.1 for Stand 2, and 44.0 and 20.7 for Stand 3, respectively. Fifteen trees were destructively harvested
for dimension analysis of component biomass (stem wood, stem bark, foliage, branches, and roots) plus N and P concentrations.
Total biomass (t ha-1) was 88.7 for Stand 1, 154.9 for Stand 2, and 278.1 for Stand 3 while N and P contents in all tree components (kg ha-1) were 483.3 and 52.2, 697.1 and 55.0, and 1113.9 and 83.7. Nitrogen concentrations were highest in the foliage, followed
by the stem bark, branches or roots, and stem wood. In contrast, P concentrations were greatest in the roots, then foliage,
branches, stem bark, and stem wood. In general, N and P concentrations in these components significantly decreased with tree
age and DBH, while N and P contents significantly increased with age and size. These relationships were stronger for size
than for age. Our current data could be utilized to estimate N and P budgets for silvicultural practices, including fertilization,
thinning, and harvesting. 相似文献
996.
Monica R. Canelhas Anne C. Barbosa Adriana O. Medeiros Ching-Fu Lee Li-Yin Huang Marc-André Lachance Carlos A. Rosa 《Antonie van Leeuwenhoek》2011,99(2):241-247
Two novel ascomycetous yeast species, Saturnispora serradocipensis and Saturnispora gosingensis, were isolated from leaf detritus in a tropical stream of Southeastern Brazil and a mushroom collected in Taiwan, respectively.
Analysis of the D1/D2 domains of the large-subunit of the rRNA gene of these strains showed that these species are related
to Saturnispora hagleri, their closest relative. Saturnispora serradocipensis and S. gosingensis differed from S. hagleri, respectively, by seven nucleotide substitutions and two indels and three nucleotide substitutions and three indels in D1/D2
rRNA sequences. The two new species differ from each another by four nucleotide substitutions and one indel in D1/D2 rRNA
sequences. However, the ITS sequences of S. serradocipensis, S. gosingensis and S. hagleri were quite divergent, showing that they are genetically separate species. The type strain of S. serradocipensis is UFMG-DC-198T (=CBS 11756T = NRRL Y-48717T), and of S. gosingensis GA4M05T is (CBS 11755T = NRRL Y-48718T). 相似文献
997.
Plants infected with vertically transmitted fungal endophytes carry their microbial symbionts with them during dispersal into
new areas. Yet, whether seed-borne endophytes enhance the host plant’s ability to overcome colonisation barriers and to regenerate
within invaded sites remains poorly understood. We examined how symbiosis with asexual endophytic fungi (Neotyphodium) affected establishment and seed loss to predators in the invasive annual grass Lolium multiflorum (Italian ryegrass) across contrasting successional plots. Italian ryegrass seeds with high and low endophyte incidence were
sown into three communities: a 1-year-old fallow field, a 15-year-old grassland, and a 24-year-old forest, which conformed
to an old-field chronosequence in the eastern Inland Pampa, Argentina. We found that endophyte infection consistently increased
host population recruitment and reproductive output. Endophyte presence also enhanced aerial biomass production of ryegrass
in a low recruitment year but not in a high recruitment year, suggesting that symbiotic effects on growth performance are
density dependent. Endophyte presence reduced seed removal by rodents, although differential predation may not account for
the increased success of infected grass populations. Overall, there was no statistical evidence for an endophyte-by-site interaction,
indicating that the fungal endosymbiont benefitted host establishment regardless of large differences in biotic and abiotic
environment among communities. Our results imply that hereditary endophytes may increase the chances for host grass species
to pass various ecological filters associated with invasion resistance across a broad range of successional habitats. 相似文献
998.
999.
The glycosyl transferase encoded by the cellulose synthase-like gene CSLD3/KJK/RHD7 (At3g03050) is required for cell wall integrity during root hair formation in Arabidopsis thaliana but it remains unclear whether it contributes to the synthesis of cellulose or hemicellulose. We identified two new alleles,
root hair-defective (rhd) 7-1 and rhd7-4, which affect the C-terminal end of the encoded protein. Like root hairs in the previously characterized kjk-2 putative null mutant, rhd7-1 and rhd7-4 hairs rupture before tip growth but, depending on the growth medium and temperature, hairs are able to survive rupture and
initiate tip growth, indicating that these alleles retain some function. At 21°C, the rhd7 tip-growing root hairs continued to rupture but at 5oC, rupture was inhibited, resulting in long, wild type-like root hairs.
At both temperatures, the expression of another root hair-specific CSLD gene, CSLD2, was increased in the rhd7-4 mutant but reduced in the kjk-2 mutant, suggesting that CSLD2 expression is CSLD3-dependent, and that CSLD2 could partially compensate for CSLD3 defects to prevent rupture at 5°C. Using a fluorescent brightener
(FB 28) to detect cell wall (1 → 4)-β-glucans (primarily cellulose) and CCRC-M1 antibody to detect fucosylated xyloglucans
revealed a patchy distribution of both in the mutant root hair cell walls. Cell wall thickness varied, and immunogold electron
microscopy indicated that xyloglucan distribution was altered throughout the root hair cell walls. These cell wall defects
indicate that CSLD3 is required for the normal organization of both cellulose and xyloglucan in root hair cell walls. 相似文献
1000.
We here report the genomic organisation of the grey mouse lemur (Microcebus murinus) MHC class II DQ and DR region based on BAC clone analysis. The sequenced Mimu-MHC haplotype spans 343 kb and encompasses the genes TAP2, DOB, DQB, DQA, DRB, DRA, BTNL2 and a further BTNL gene. The DQ and DR genes of this haplotype are not duplicated. Mimu-DOB is not transcribed and represents a pseudogene due to deletions and premature stop codons. Analysis of BAC clone DNA, a cDNA
sample and eight genomic DNA samples suggests that Mimu-DRB, Mimu-DQA and Mimu-DQB are highly polymorphic with the majority of peptide-binding residues being affected by polymorphisms. In contrast, Mimu-DRA is moderately polymorphic, and the variable amino acid positions are not part of the peptide-binding region. Phylogenetic
analysis of Mimu-DQA and Mimu-DQB and other primate DQA and DQB genes indicates that duplication of DQA and DQB loci occurred in Anthropoidea after the split from Strepsirrhini. 相似文献