Recent investigations have identified homologs of eukaryotic box C/D small nucleolar RNAs (snoRNAs) in Archaea termed sRNAs. Archaeal homologs of the box C/D snoRNP core proteins fibrillarin and Nop56/58 have also been identified but a homolog for the eukaryotic 15.5kD snoRNP protein has not been described. Our sequence analysis of archaeal genomes reveals that the highly conserved ribosomal pr...

The clustered regularly interspaced short palindromic repeat (CRISPR)-Cas system mediates adaptive immunity against foreign nucleic acids in prokaryotes. However, efficient adaptation of a native CRISPR to purified viruses has only been observed for the type II-A system from a Streptococcus thermophilus industry strain, and rarely reported for laboratory strains. Here, we provide a second nativ...

Ribonuclease P (RNase P) is the endonuclease responsible for the removal of 5' leader sequences from tRNA precursors. The crystal structure of an archaeal RNase P protein, Ph1771p (residues 36-127) from hyperthermophilic archaeon Pyrococcus horikoshii OT3 was determined at 2.0 A resolution by X-ray crystallography. The structure is composed of four helices (alpha1-alpha4) and a six-stranded ant...

Protein turnover is an essential process in living cells. The degradation of cytosolic polypeptides is mainly carried out by the proteasome, resulting in 7-9-amino acid long peptides. Further degradation is usually carried out by energy-independent proteases like the tricorn protease from Thermoplasma acidophilum. Recently, a novel tetrahedral-shaped dodecameric 480-kDa aminopeptidase complex (...

Until recently, extremely halophilic euryarchaeota were considered mostly as aerobic heterotrophs utilizing simple organic compounds as growth substrates. Almost nothing is known on the ability of these prokaryotes to utilize complex polysaccharides, such as cellulose, xylan, and chitin. Although few haloarchaeal cellulases and chitinases were recently characterized, the analysis of currently a...

a 3-month-old short haired pointer with crusty local alopecia around the eyes was presented to smallanimal hospital of tehran university. scraping and biopsy were obtained from lesions of affected area.notoedres sp. was diagnosed in skin scraping by parasitologic examination. furthermore, histopathology oflesions demonstrated moderate hyperplastic epidermis, parakeratosis and acanthosis.

  Various parasite species were found in Carassius carassius including Diplostomum spathaceum, Dactylogyrus sp.,Gyrodactylus sp. Ichthyophthirius multifiliis and Trichodinia sp . They were found in four rivers in West Azerbaijan Province (North-Western Iran) . A total of 207 live Carassius carassius from four rivers including Aras (72) Zariyneh (42) Nazlo (58) and Barandoz (35) were studied. Pa...

screening and identification of moderately halophilic protease producing bacteria from different regions of maharloo, a hypersaline lake in the southern area of iran, were the objectives of this study. in the preliminary screening, 16 isolates exhibited proteolytic activity on saline skim milk agar. all isolates were able to grow comfortably in the media containing 7-15% of salt. protease activ...

contamination of human and animal body tissues with flies’ larvae and diptera cause myiasis. a 26 yr old female patient refers to kashan shahid beheshti hospital, central iran because of urogenital infection, pain in the right part of stomach, smelly and reddish vaginal discharge and frequent urination. in the first checking, urine sample was taken. in the sample, active and alive larvae were s...