سابقه و هدف: جنگل­ های زاگرس به ­عنوان یکی از بوم ­سازگان­ جنگلی مهم ایران پوشش­ گیاهی (درختان، درختچه ­ها گونه­ علفی) متنوعی برخوردار می­ باشد. شناسایی آگاهی دقیق نقش ­شناختی آنها در این ­سازگان تواند حفاظت منابع طبیعی توسعه پایدار کمک شایانی نماید. به‌منظور مطالعه تنوع گونه‌ای گیاهان چوبی ذخیره کربن خاک رابطه با عوامل فیزیوگرافیک (جهت، شیب ارتفاع سطح دریا)، رویشگاه کیکم (var. cinerascens Acer...

In eukaryotes, Dom34 is involved in the rescue of ribosomes that stall on mRNAs during protein synthesis. Using ribosome profiling, Guydosh and Green reveal that, in addition to rescue of ribosomes stalled on truncated mRNAs, Dom34 also recycles ribosomes that are unexpectedly found in the 3' untranslated regions of many cellular mRNAs.

I . Nascent translation products on mitochondrial ribosomes were selectively labeled in vivo in the presence of cycloheximide with radioactive leucine. They were isolated together with the ribosomes. 2. The labeled polypeptides show a high tendency to aggregate and can only be kept in solution in the presence of detergents such as dodecylsulfate. Also, mitochondrial ribosomes carrying nascent p...

Ribosome recycling factor (RRF), elongation factor-G (EF-G), and ribosomes from Thermus thermophilus (tt-) and Escherichia coli (ec-) were used to study the disassembly mechanism of post-termination ribosomal complexes by these factors. With tt-RRF, ec-EF-G can release bound-tRNA from ec-model post-termination complexes. However, tt-RRF is not released by ec-EF-G from ec-ribosomes. This complex...

Antibiotics were used as probes of ribosome topology and function. Studies of [(14)C]chloramphenicol and [(14)C]erythromycin binding to ribosomes and polyribosomes revealed the following features. The requirement of high K(+) concentration (150 mM) for [(14)C]chloramphenicol binding to NH(4)Cl-washed ribosomes resulted from the washing procedure. Neither native 70S ribosomes nor polyribosomes r...

Radioactive amino acids were incorporated in vivo into Neurospora crassa cells, and the mitochondrial ribosomes were isolated. The incorporat,ion of radioactivity into the proteins of these ribosomes was inhibited by cycloheximide, but not by chloramphenicol. It is therefore concluded that these proteins are synthesized on the cycloheximide sensitive and chloramphenicol insensitive cytoplasmic ...

Each major component of the proteins of 30S ribosomes from Escherichia coli was compared with the proteins of 50S ribosomes. The comparisons were done by using polyacrylamide gel electrophoresis in urea with differentially labeled proteins. The data show that no major protein is common to both ribosomes.

Ribosomal subunits were prepared from fungal spore ribosomes and reassociated to yield biologically active ribosomes.

Growing yeast spheroplasts were shown to have, on the average, four times the number of cytoplasmic ribosomes in contact with the outer mitochondrial membrane compared to starved spheroplasts. Ribosomes in contact with mitochondria in the growing spheroplast preparation, like free cytoplasmic ribosomes, exist primarily as polysome structures. In the starved spheroplast preparation, both mitocho...

Ribosomes of streptomycin-resistant strains (&r-R) translate genetic messages with fewer errors than ribosomes of streptomycin-sensitive (S&S) strains. I have examined whether the increased level of tRNA discrimination by &r-R ribosomes, relative to Str-S ribosomes, occurs in an initial discrimination step before GTP hydrolysis during enzymatic tRNA binding, or in a second discrimination, or pr...