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121.
Recently Mycobacterium tuberculosis was shown to possess a novel protein modification, in which a small protein Pup is conjugated to the epsilon-amino groups of lysines in target proteins. Analogous to ubiquitin modification in eukaryotes, this remarkable modification recruits proteins for degradation via archaeal-type proteasomes found in mycobacteria and allied actinobacteria. While a mycobacterial protein named PafA was found to be required for this conjugation reaction, its biochemical mechanism has not been elucidated. Using sensitive sequence profile comparison methods we establish that the PafA family proteins are related to the γ-glutamyl-cysteine synthetase and glutamine synthetase. Hence, we predict that PafA is the Pup ligase, which catalyzes the ATP-dependent ligation of the terminal γ-carboxylate of glutamate to lysines, similar to the above enzymes. We further discovered that an ortholog of the eukaryotic PAC2 (e.g. cg2106) is often present in the vicinity of the actinobacterial Pup-proteasome gene neighborhoods and is likely to represent the ancestral proteasomal chaperone. Pup-conjugation is sporadically present outside the actinobacteria in certain lineages, such as verrucomicrobia, nitrospirae, deltaproteobacteria and planctomycetes, and in the latter two lineages it might modify membrane proteins. 相似文献
122.
123.
Eman M. Fayed Ahmed M. Abd-EIGawad Abdelsamed I. Elshamy El-Sayed F. El-Halawany Yasser A. EI-Amier 《化学与生物多样性》2021,18(4):e2000914
Essential oils (EOs) are a promising group of natural products of the aromatic plants due to their various biological effects such as allelopathic, antioxidant, antimicrobial activities. The present study aimed to construct the detailed chemical profile of the EO derived from Deverra tortuosa aerial parts along with assessing its allelopathic, antimicrobial, and antioxidant potentialities. The EO was extracted by hydrodistillation and analyzed via gas chromatography-mass spectrometry (GC/MS). The allelopathic activity of the EO was assessed against the germination and seedling growth of the weed Chenopodium murale. Also, the EO was tested against five microbes. The antioxidant activity was determined using the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The GC/MS analysis of EO revealed the presence of 86 compounds with a preponderance of oxygenated sesquiterpenes and monoterpene hydrocarbons. Widdrol, β-phellandrene, piperitol, cubedol, α-terpinene, (E)-10-heptadecen-8-ynoic acid methyl ester, citronellyl tiglate, and m-cymene were the major compounds. A comparative profile was established between the EOs constituents of our study with the documented EOs of D. tortuosa and the other Deverra species around the world via agglomerative hierarchical clustering (AHC) and principal components analysis (PCA). The EO showed a substantial allelopathic activity against C. murale, as well as it showed considerable antimicrobial and antioxidant activities. Thereby, the EO of D. tortuosa could be considered as a promising environmental-friendly bioherbicide against weeds. Also, it could be integrated into food preservation due to its potent antimicrobial and antioxidant activities. However, further study is recommended for more characterization of the major compounds and evaluation of their activities, either singular or synergistic, and assess their efficiency and biosafety. 相似文献
124.
Szklarczyk R Wanschers BF Cuypers TD Esseling JJ Riemersma M van den Brand MA Gloerich J Lasonder E van den Heuvel LP Nijtmans LG Huynen MA 《Genome biology》2012,13(2):R12-14
Background
Orthology is a central tenet of comparative genomics and ortholog identification is instrumental to protein function prediction. Major advances have been made to determine orthology relations among a set of homologous proteins. However, they depend on the comparison of individual sequences and do not take into account divergent orthologs.Results
We have developed an iterative orthology prediction method, Ortho-Profile, that uses reciprocal best hits at the level of sequence profiles to infer orthology. It increases ortholog detection by 20% compared to sequence-to-sequence comparisons. Ortho-Profile predicts 598 human orthologs of mitochondrial proteins from Saccharomyces cerevisiae and Schizosaccharomyces pombe with 94% accuracy. Of these, 181 were not known to localize to mitochondria in mammals. Among the predictions of the Ortho-Profile method are 11 human cytochrome c oxidase (COX) assembly proteins that are implicated in mitochondrial function and disease. Their co-expression patterns, experimentally verified subcellular localization, and co-purification with human COX-associated proteins support these predictions. For the human gene C12orf62, the ortholog of S. cerevisiae COX14, we specifically confirm its role in negative regulation of the translation of cytochrome c oxidase.Conclusions
Divergent homologs can often only be detected by comparing sequence profiles and profile-based hidden Markov models. The Ortho-Profile method takes advantage of these techniques in the quest for orthologs. 相似文献125.
Hegazy ME Gamal-Eldeen AM El-Halawany AM Mohamed Ael-H Paré PW 《Cell biochemistry and biophysics》2012,63(1):85-96
Suspension of cultured cells of Marchantia polymorpha have the potential to hydrogenate the olefinic bonds present in androst-1,4-dien-3,17-dione (boldione, 1) to afford dihydroandrost-3,17-dione derivatives including: androst-4-ene-3,17-dione (androstenedione, 4-AD, 2), 5α-androstane-3,17-dione (androstenedione, AD, 4), and the less abundant metabolite 5α-androst-1-ene-3,17-dione (1-androstenedione, 1-AD, 3). After isolation and purification, these metabolites were characterized on the basis of spectroscopic analyses using 1D
and 2D NMR as well as mass spectrometry. Cytotoxicity of the biotransformation products against breast adenocarcinoma cells
(MCF-7) was assessed by a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay and cell death (apoptosis
or necrosis) was assayed by acridine orange/ethidium bromide staining. Aromatase (cytochrome P450 19 enzyme, CYP19) inhibitory
activity was measured by a tritiated water release assay and by direct measurement of bio-transformed steroids using the tritium
labeled substrate 3H-androst-4-ene-3,17-dione. CYP19 mRNA expression in MCF-7 cells was analyzed by real-time PCR. Steroidal products 3 and 4 revealed a highly significant inhibition of MCF-7 cell growth that was predominantly due to apoptosis not necrosis. Steroidal
products 3 and 4 are both potent inhibitors of aromatase activity and CYP19 mRNA expression, while 2 is a known substrate for aromatase. These data establish that metabolites 3 and 4 are potent chemical agents against breast cancer via aromatase inhibitory mechanism. Results were interpreted via virtual
docking of the biotransformation products to the human placental aromatase active site. 相似文献
126.
Structural genes of the mouse major urinary protein are on chromosome 4 总被引:10,自引:0,他引:10
The major urinary proteins (MUPs) of mouse are a family of at least three major proteins which are synthesized in the liver of all strains of mice. The relative levels of synthesis of these proteins with respect to each other in the presence of testosterone is regulated by the Mup-a locus located on chromosome 4. In an effort to determine the mechanism of this regulation in molecular terms, a cDNA clone containing most of the coding region of a MUP protein has been isolated and identified by partial DNA sequence analysis. Using a combination of hybridization analysis and somatic cell genetics, the structural gene family has been unambiguously mapped to mouse chromosome 4. These data suggest that Mup-a regulation operates in a cis fashion and that models proposing trans regulation of MUP protein synthesis are unlikely. 相似文献
127.
K. H. Shaltout E. F. El-Halawany M. M. El-Garawany 《Biodiversity and Conservation》1997,6(7):1027-1040
This study assesses the plant communities and environmental factors that govern species richness and distribution in the coastal
lowlands of eastern Saudi Arabia using TWINSPAN, DCA and regression analyses. Thirty-four vegetation groups were identified,
some of these occur in only one habitat: Juncus rigidus and Aeluropus lagopoides-Phragmites australis in the high saline flats,
Plantago boissieri-Savignya parviflora, Panicum turgidum-Plantago boissieri-Moltkiopsis ciliata and Panicum turgidum-Haloxylon
salicornicum in the non-saline flats, and Bassia eriophora-Launaea mucronata in the depressions between dunes. Some other
groups are represented in at least four out of six studied habitats: Zygophyllum qatarense-Launaea capitata-Plantago boissieri,
Zygophyllum qatarense-Plantago boissieri and Haloxylon salicornicum-Zygophyllum qatarense. Among 20 examined soil and community
variables, regression analysis indicates that only six are influential in the stand ordination process (K, lime, sulphates,
pH, plant cover and species richness). Some human impacts (e.g. grazing and cutting intensities) also play an important role.
The nature of soil surface and salinity are the main factors that affect the species richness.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
128.
Alpina Begossi Svetlana V Salivonchyk Luciana G Araujo Tainá B Andreoli Mariana Clauzet Claudia M Martinelli Allan GL Ferreira Luiz EC Oliveira Renato AM Silvano 《Journal of ethnobiology and ethnomedicine》2011,7(1):1-23
In this study, we sought to investigate the biology (diet and reproduction) and ethnobiology (fishers knowledge and fishing spots used to catch snappers) of five species of snappers (Lutjanidae), including Lutjanus analis, Lutjanus synagris, Lutjanus vivanus, Ocyurus chrysurus, and Romboplites saliens at five sites along the northeast (Riacho Doce, Maceió in Alagoas State, and Porto do Sauípe, Entre Rios at Bahia State) and the southeast (SE) Brazilian coast (Paraty and Rio de Janeiro cities at Rio de Janeiro State, and Bertioga, at São Paulo State.). We collected 288 snappers and interviewed 86 fishermen. The stomach contents of each fish were examined and macroscopic gonad analysis was performed. Snappers are very important for the fisheries of NE Brazil, and our results indicated that some populations, such as mutton snapper (L. analis) and lane snapper (L. synagris), are being caught when they are too young, at early juvenile stages. Local knowledge has been shown to be a powerful tool for determining appropriate policies regarding management of target species, and artisanal fishermen can be included in management processes. Other suggestions for managing the fisheries are discussed, including proposals that could provide motivation for artisanal fishermen to participate in programs to conserve resources, such as co-management approaches that utilize local knowledge, the establishment of fishing seasons, and compensation of fishermen, through 'payment for environmental services'. These suggestions may enhance the participation of local artisanal fishermen in moving to a more realistic and less top-down management approach of the fish population. 相似文献
129.
A report on the 11th Cold Spring Harbor Laboratory/Wellcome Trust conference on Genome Informatics, Cold Spring Harbor Laboratories,
New York, USA, November 2-5, 2011. 相似文献
130.