Elongation factor (EF) G promotes tRNA translocation on the ribosome. We present three-dimensional reconstructions, obtained by cryo-electron microscopy, of EF-G-ribosome complexes before and after translocation. In the pretranslocation state, domain 1 of EF-G interacts with the L7/12 stalk on the 50S subunit, while domain 4 contacts the shoulder of the 30S subunit in the region where protein S...

In Escherichia coli, secretory proteins (preproteins) are translocated across the cytoplasmic membrane by the Sec system composed of a protein-conducting channel, SecYEG, and an ATP-dependent motor protein, SecA. After binding of the preprotein to SecYEG-bound SecA, cycles of ATP binding and hydrolysis by SecA are thought to drive the stepwise translocation of the preprotein across the membrane...

The twin-arginine translocation (Tat) system transports folded proteins of various sizes across both bacterial and plant thylakoid membranes. The membrane-associated TatA protein is an essential component of the Tat translocon, and a broad distribution of different sized TatA-clusters is observed in bacterial membranes. We assume that the size dynamics of TatA clusters are affected by substrate...

In unicellular organisms like yeasts, which do not have specialized tissues for protection against environmental challenges, the presence of cellular mechanisms to respond and adapt stress conditions is fundamental. this work, we aimed investigate response light in Kluyveromyces lactis . Yeast lacks light-sensing proteins; however, Saccharomyces cerevisiae has been reported by increasing hydrog...

The translocation of lipids from the inner to the outer membrane of Escherichia coli has been investigated by pulse-chase experiments. After a pulse with [2-3H]glycerol, the specific activity of the newly synthesized [3H]phosphatidylethanolamine was 5 times greater in the inner than in the outer membrane. During the chase, [3H]phosphatidylethanolamine was translocated to the outer membrane. At ...

background: primary gastric lymphoma (pgl) is an uncommon malignancy with various histological subtypes and treatment outcomes. the aim of this study was to investigate the potential prognostic factors and clinicopathological characteristics of iranian patients with pgl. methods: the clinicopathological characteristics of 60 patients with pgl were retrospectively reviewed from 2001 to 2012. the...

health price inflation rate is different from increasing in health expenditures. health expenditures contain both quantity and prices but inflation rate contains prices. this study aimed to determine the factors that affect the inflation rate for health care services (ircpihc) in iran.we used central bank of iran data. we estimated the relationship between the inflation rate and its determinant...

background: so far, many studies investigated factors that affect pregnancy rates after intrauterine insemination (iui). various investigators have not agreed on the nature and ranking of these criteria. objective: the aim of this study was to assess the predictive factors for pregnancy rate after controlled ovarian hyperstimulation (coh)/ iui. materials and methods: retrospective study of all ...

background: in this study, the early effects of percutaneous nephrolithotomy (pcnl) on glomerular filtration rate (gfr) was assessed in different postoperative times and likewise, we determined the correlation of different variables with significant postoperative gfr drop  after pcnl. m aterials and methods: patient records of 486 cases that had undergone pcnl from january 2010 to october 2011 ...