154 research outputs found
Number of natively unfolded proteins scales with genome size
Natively unfolded proteins exist as an ensemble of flexible conformations
lacking a well defined tertiary structure along a large portion of their
polypeptide chain. Despite the absence of a stable configuration, they are
involved in important cellular processes. In this work we used from three
indicators of folding status, derived from the analysis of mean packing and
mean contact energy of a protein sequence as well as from VSL2, a disorder
predictor, and we combined them into a consensus score to identify natively
unfolded proteins in several genomes from Archaea, Bacteria and Eukarya. We
found a high correlation among the number of predicted natively unfolded
proteins and the number of proteins in the genomes. More specifically, the
number of natively unfolded proteins scaled with the number of proteins in the
genomes, with exponent 1.81 +- 0.10. This scaling law may be important to
understand the relation between the number of natively unfolded proteins and
their roles in cellular processes.Comment: Submitted to Biophysics and Bioengineering Letters
http://padis2.uniroma1.it:81/ojs/index.php/CISB-BB
Codon Bias Patterns of 's Interacting Proteins
Synonymous codons, i.e., DNA nucleotide triplets coding for the same amino
acid, are used differently across the variety of living organisms. The
biological meaning of this phenomenon, known as codon usage bias, is still
controversial. In order to shed light on this point, we propose a new codon
bias index, , that is based on the competition between cognate and
near-cognate tRNAs during translation, without being tuned to the usage bias of
highly expressed genes. We perform a genome-wide evaluation of codon bias for
, comparing with other widely used indices: , , and
. We show that and capture similar information by being
positively correlated with gene conservation, measured by ERI, and
essentiality, whereas, and appear to be less sensitive to
evolutionary-functional parameters. Notably, the rate of variation of and
with ERI allows to obtain sets of genes that consistently belong to
specific clusters of orthologous genes (COGs). We also investigate the
correlation of codon bias at the genomic level with the network features of
protein-protein interactions in . We find that the most densely
connected communities of the network share a similar level of codon bias (as
measured by and ). Conversely, a small difference in codon bias
between two genes is, statistically, a prerequisite for the corresponding
proteins to interact. Importantly, among all codon bias indices, turns
out to have the most coherent distribution over the communities of the
interactome, pointing to the significance of competition among cognate and
near-cognate tRNAs for explaining codon usage adaptation
Sediment features and heavy metal levels in four areas of Sardinia devoted to bivalve culture = Caratteristiche dei sedimenti e livelli di metalli pesanti in quattro aree della Sardegna idonee all’allevamento dei bivalvi
Sediment characteristics and Cd, Cu, Mn, Pb and Zn concentrations were assessed in the
lagoons of Marceddì, Calich and Porto Pozzo, and in the inner part of the Gulf of Olbia. Sediment of the
zones examined were quite similar, except for the Calich lagoon that showed the higher content of total
organic carbon. High values of Cd, Pb and Zn were detected in the sediments of the Marceddì lagoon,
while remarkable levels of Cu and Mn were found in the Calich lagoon and in the Gulf of Olbia
L'Invecchiamento biologico del Cannonau di Oliena
Accelerated ageing trials were carried out on « Cannonau di Oliena» under production conditions.
Yeast «Flor» strains of the species Saccharomyces prostoserdovii were used as ageing agents.
Results showed that wines produced using these yeasts were superior to those produced normally
specially when Sacch. Prostoserdovii was added to the musts as «pied de cuve», thus reducing
maturing times considerably
Produzione di anidride solforosa da parte dei lieviti nel corso della fermentazione alcolica
SO2 production by yeast during alcoholic fermentation. Determinations were made of SO2 produced during
must fermentation by 29 strains of Saccharomyces cerevisiae. After 2 days of fermentation, only 4 reached
a 50 - 70 mg/l SO2 production; on the 4th day only 2; and on the 7th day only 1. All proved to belong
to the low SO2 producer category
Aerobic and anaerobic spore-forming bacteria in Sardinian honey.
Apart from an ubiquitous microflora, this investigation into 52 samples of honey revealed some undesirable
spore-forming bacteria, Bacillus alvei and B. larvae which are bee pathogens. Bacillus cereus can cause
spoilage and food poisoning.
It is, therefore, considered essential that every country includes microbiological standards in its Food Safety
Regulations for honey, so that the consumer is guaranteed as to the wholesomeness as well as the quality
of the product
I Lieviti del tubo digerente dell'<i>Apis inellifica ligustica</i> Spinola
The results of microbiological surveis of apis mellifica lingustica Spinola intestinal tacts are givenhere. From 100 samples 54 yeast strains were isolated. The yeast specie identified are: H. anomala var. schneggii, C. guilliermondii var. guilliermondii, T. apicola, T. candida, T. glabrata, T. haemulonii.
The yeast species isolated were not so different from those discovered by other authors in similar environments
- …