Abstract:
:In bacteria, elongation factor Tu is a translational cofactor that forms ternary complexes with aminoacyl-tRNA (aa-tRNA) and GTP. Binding of a ternary complex to one of four flexible L7/L12 units on the ribosome tethers a charged tRNA in close proximity to the ribosomal A site. Two sequential tests for a match between the aa-tRNA anticodon and the current mRNA codon then follow. Because one elongation cycle can occur in as little as 50 ms and the vast majority of aa-tRNA copies are not cognate with the current mRNA codon, this testing must occur rapidly. We present a single-molecule localization and tracking study of fluorescently labeled EF-Tu in live Escherichia coli Imaging at 2 ms/frame distinguishes 60% slowly diffusing EF-Tu copies (assigned as transiently bound to translating ribosome) from 40% rapidly diffusing copies (assigned as a mixture of free ternary complexes and free EF-Tu). Combining these percentages with copy number estimates, we infer that the four L7/L12 sites are essentially saturated with ternary complexes in vivo. The results corroborate an earlier inference that all four sites can simultaneously tether ternary complexes near the A site, creating a high local concentration that may greatly enhance the rate of testing of aa-tRNAs. Our data and a combinatorial argument both suggest that the initial recognition test for a codon-anticodon match occurs in less than 1 to 2 ms per aa-tRNA copy. The results refute a recent study (A. Plochowietz, I. Farrell, Z. Smilansky, B. S. Cooperman, and A. N. Kapanidis, Nucleic Acids Res 45:926-937, 2016, https://doi.org/10.1093/nar/gkw787) of tRNA diffusion in E. coli that inferred that aa-tRNAs arrive at the ribosomal A site as bare monomers, not as ternary complexes.IMPORTANCE Ribosomes catalyze translation of the mRNA codon sequence into the corresponding sequence of amino acids within the nascent polypeptide chain. Polypeptide elongation can be as fast as 50 ms per added amino acid. Each amino acid arrives at the ribosome as a ternary complex comprising an aminoacyl-tRNA (aa-tRNA), an elongation factor called EF-Tu, and GTP. There are 43 different aa-tRNAs in use, only one of which typically matches the current mRNA codon. Thus, ternary complexes must be tested very rapidly. Here we use fluorescence-based single-molecule methods that locate and track single EF-Tu copies in E. coli Fast and slow diffusive behavior determines the fraction of EF-Tu copies that are ribosome bound. We infer simultaneous tethering of ~4 ternary complexes to the ribosome, which may facilitate rapid initial testing for codon matching on a time scale of less than 1 to 2 ms per aa-tRNA.
journal_name
mBiojournal_title
mBioauthors
Mustafi M,Weisshaar JCdoi
10.1128/mBio.02143-17subject
Has Abstractpub_date
2018-01-16 00:00:00issue
1issn
2150-7511pii
mBio.02143-17journal_volume
9pub_type
杂志文章相关文献
mBio文献大全abstract::The intracellular parasite Toxoplasma gondii employs a vast array of effector proteins from the rhoptry and dense granule organelles to modulate host cell biology; these effectors are known as ROPs and GRAs, respectively. To examine the individual impacts of ROPs and GRAs on host gene expression, we developed a robust...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.00182-20
更新日期:2020-06-09 00:00:00
abstract::Members of the genus Mycobacterium are the most prevalent cause of infectious diseases. Mycobacteria have a complex cell envelope containing a peptidoglycan layer and an additional arabinogalactan polymer to which a mycolic acid bilayer is linked; this complex, multilayered cell wall composition (mAGP) is conserved am...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.02213-16
更新日期:2017-02-07 00:00:00
abstract:UNLABELLED:Sensing of and responding to environmental changes are of vital importance for microbial cells. Consequently, bacteria have evolved a plethora of signaling systems that usually sense biochemical cues either via direct ligand binding, thereby acting as "concentration sensors," or by responding to downstream e...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.00975-15
更新日期:2015-07-21 00:00:00
abstract:UNLABELLED:Marine methane seeps are globally distributed geologic features in which reduced fluids, including methane, are advected upward from the subsurface. As a result of alkalinity generation during sulfate-coupled methane oxidation, authigenic carbonates form slabs, nodules, and extensive pavements. These carbona...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01348-15
更新日期:2015-12-22 00:00:00
abstract::SARS-CoV-2 uses human angiotensin-converting enzyme 2 (ACE2) as the primary receptor to enter host cells and initiate the infection. The critical binding region of ACE2 is an ∼30-amino-acid (aa)-long helix. Here, we report the design of four stapled peptides based on the ACE2 helix, which is expected to bind to SARS-C...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.02451-20
更新日期:2020-12-11 00:00:00
abstract::Heme oxygenase-1 (HO-1) is a stress response antioxidant enzyme which catalyzes the degradation of heme released during inflammation. HO-1 expression is upregulated in both experimental and human Mycobacterium tuberculosis infection, and in patients it is a biomarker of active disease. Whether the enzyme plays a prote...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01675-16
更新日期:2016-10-25 00:00:00
abstract::Throughout history, the yeast Saccharomyces cerevisiae has played a central role in human society due to its use in food production and more recently as a major industrial and model microorganism, because of the many genetic and genomic tools available to probe its biology. However, S. cerevisiae has proven difficult ...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01410-18
更新日期:2018-09-25 00:00:00
abstract:UNLABELLED:Promiscuous plasmids replicate in a wide range of bacteria and therefore play a key role in the dissemination of various host-beneficial traits, including antibiotic resistance. Despite the medical relevance, little is known about the evolutionary dynamics through which drug resistance plasmids adapt to new ...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.00077-12
更新日期:2012-07-03 00:00:00
abstract::Increasing evidence has indicated that single nucleotide polymorphisms (SNPs) are related to the susceptibility of sepsis and might provide potential evidence for the mechanisms of sepsis. Our recent preliminary study showed that the ADAM10 genetic polymorphism was clinically associated with the development of sepsis,...
journal_title:mBio
pub_type: 杂志文章,多中心研究
doi:10.1128/mBio.01663-19
更新日期:2019-08-06 00:00:00
abstract::Despite their exceptional potencies, the broad tropism of most commonly used lentivirus (LV) vectors limits their use for targeted gene delivery in vivo We hypothesized that we could improve the specificity of LV targeting by coupling (i) reduction of their binding to off-target cells with (ii) redirection of the vect...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.02990-19
更新日期:2020-01-21 00:00:00
abstract:UNLABELLED:Salmonella enterica serovar Typhimurium is one of the most common S. enterica serovars associated with U.S. foodborne outbreaks. S. Typhimurium bacteria isolated from humans exhibit wide-ranging virulence phenotypes in inbred mice, leading to speculation that some strains are more virulent in nature. However...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.00154-16
更新日期:2016-03-08 00:00:00
abstract::The apparent mislocalization or excretion of cytoplasmic proteins is a commonly observed phenomenon in both bacteria and eukaryotes. However, reports on the mechanistic basis and the cellular function of this so-called "nonclassical protein secretion" are limited. Here we report that protein overexpression in recombin...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.02118-17
更新日期:2018-01-30 00:00:00
abstract::Listeria monocytogenes is a bacterial pathogen causing severe foodborne infections in humans and animals. Listeria can enter into host cells and survive and multiply therein, due to an arsenal of virulence determinants encoded in different loci on the chromosome. Several key Listeria virulence genes are clustered in L...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01550-17
更新日期:2017-10-31 00:00:00
abstract:UNLABELLED:Ebola viruses (EBOV) cause severe disease in humans and nonhuman primates with high mortality rates and continue to emerge in new geographic locations, including several countries in West Africa, the site of a large ongoing outbreak. Phosphorodiamidate morpholino oligomers (PMOs) are synthetic antisense mole...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.02344-14
更新日期:2015-02-10 00:00:00
abstract::The hospital environment is a potential reservoir of bacteria with plasmids conferring carbapenem resistance. Our Hospital Epidemiology Service routinely performs extensive sampling of high-touch surfaces, sinks, and other locations in the hospital. Over a 2-year period, additional sampling was conducted at a broader ...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.02011-17
更新日期:2018-02-06 00:00:00
abstract:UNLABELLED:Osteomyelitis is a difficult-to-eradicate bone infection typically caused by Staphylococcus aureus. In this study, we investigated the in vivo transcriptional adaptation of S. aureus during bone infection. To this end, we determined the transcriptome of S. aureus during the acute (day 7) and chronic (day 28)...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01775-14
更新日期:2014-12-23 00:00:00
abstract::Influenza virus hemagglutinin (HA) surface glycoprotein is currently the primary target of licensed influenza vaccines. Recently, broadly reactive antibodies that target the stalk region of the HA have become a major focus of current novel vaccine development. These antibodies have been observed in humans after natura...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.02284-17
更新日期:2018-01-23 00:00:00
abstract:UNLABELLED:Kaposi's sarcoma (KS), caused by KS-associated herpesvirus (KSHV), is the most common cancer among HIV-infected patients in Malawi and in the United States today. In Malawi, KSHV is endemic. We conducted a cross-sectional study of patients with HIV infection and KS with no history of chemo- or antiretroviral...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01633-14
更新日期:2014-09-23 00:00:00
abstract::DNA supercoiling (DS) is essential for life because it controls critical processes, including transcription, replication, and recombination. Current methods to measure DNA supercoiling in vivo are laborious and unable to examine single cells. Here, we report a method for high-throughput measurement of bacterial DNA su...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01053-20
更新日期:2020-07-28 00:00:00
abstract::ABSTRACT The type VII secretion systems are conserved across mycobacterial species and in many Gram-positive bacteria. While the well-characterized Esx-1 pathway is required for the virulence of pathogenic mycobacteria and conjugation in the model organism Mycobacterium smegmatis, Esx-3 contributes to mycobactin-media...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01073-14
更新日期:2014-05-06 00:00:00
abstract::Pathogens frequently employ eukaryotic linear motif (ELM)-rich intrinsically disordered proteins (IDPs) to perturb and hijack host cell networks for a productive infection. Mycobacterium tuberculosis has a relatively high percentage of IDPs in its proteome, the significance of which is not known. The Mycobacterium-spe...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01712-17
更新日期:2018-01-23 00:00:00
abstract::The proteasome is a major protein degradation machinery with essential and diverse biological functions. Upon induction by cytokines, proteasome subunits β1, β2, and β5 are replaced by β1i/LMP2, β2i/MECL-1, and β5i/LMP7, resulting in the formation of an immunoproteasome (iProteasome). iProteasome-degraded products are...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.02221-19
更新日期:2020-10-27 00:00:00
abstract::Nineteen Thermococcus kodakarensis strains have been constructed, each of which synthesizes a different His(6)-tagged protein known or predicted to be a component of the archaeal DNA replication machinery. Using the His(6)-tagged proteins, stable complexes assembled in vivo have been isolated directly from clarified c...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.00221-10
更新日期:2010-10-26 00:00:00
abstract::Influenza A viruses cause an annual contagious respiratory disease in humans and are responsible for periodic high-mortality human pandemics. Pandemic influenza A viruses usually result from the reassortment of gene segments between human and avian influenza viruses. These avian influenza virus gene segments need to a...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01222-18
更新日期:2018-07-03 00:00:00
abstract::Aspergillus fumigatus is the leading cause of pulmonary fungal diseases. Azoles have been used for many years as the main antifungal agents to treat and prevent invasive aspergillosis. However, in the last 10 years there have been several reports of azole resistance in A. fumigatus and new strategies are needed to com...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.00816-20
更新日期:2020-06-16 00:00:00
abstract::The four dengue virus serotypes (DENV1 to 4) cause dengue, a major public health problem worldwide. Individuals exposed to primary DENV infections develop serotype-specific neutralizing antibodies, including strongly neutralizing antibodies targeting quaternary epitopes. To date, no studies have measured the levels an...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01205-17
更新日期:2017-09-19 00:00:00
abstract::Bacteroides thetaiotaomicron is one of the most abundant gut symbiont species, whose contribution to host health through its ability to degrade dietary polysaccharides and mature the immune system is under intense scrutiny. In contrast, adhesion and biofilm formation, which are potentially involved in gut colonization...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.00729-20
更新日期:2020-06-23 00:00:00
abstract:UNLABELLED:Recent studies strongly suggest that the gene expression sustaining both normal and pathogenic bacterial growth is governed by the structural dynamics of the chromosome. However, the mechanistic device coordinating the chromosomal configuration with selective expression of the adaptive traits remains largely...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.00353-15
更新日期:2015-04-28 00:00:00
abstract:UNLABELLED:A mechanistic understanding of the determination and maintenance of the simplest bacterial cell shape, a sphere, remains elusive compared with that of more complex shapes. Cocci seem to lack a dedicated elongation machinery, and a spherical shape has been considered an evolutionary dead-end morphology, as a ...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.00908-16
更新日期:2016-09-06 00:00:00
abstract::Peptides that are synthesized independently of the ribosome in plants, fungi, and bacteria can have clinically relevant anticancer, antihemochromatosis, and antiviral activities, among many other. Despite their natural origin, discovering new natural products is challenging, and there is a need to expand the chemical ...
journal_title:mBio
pub_type: 杂志文章
doi:10.1128/mBio.01474-17
更新日期:2017-10-10 00:00:00