scholarly journals Partition of tRNAGly isoacceptors between protein and cell-wall peptidoglycan synthesis in Staphylococcus aureus

2020 ◽  
Author(s):  
Lauriane Rietmeyer ◽  
Nicolas Fix-Boulier ◽  
Chloé Le Fournis ◽  
Laura Iannazzo ◽  
Camelia Kitoun ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Elongation Factor ◽  
Side Chain ◽  
Messenger Rnas ◽  
Translation Elongation ◽  
Trna Synthetases ◽  
Cell Wall Peptidoglycan ◽  
Multiple Interactions

Abstract The sequence of tRNAs is submitted to evolutionary constraints imposed by their multiple interactions with aminoacyl-tRNA synthetases, translation elongation factor Tu in complex with GTP (EF-Tu•GTP), and the ribosome, each being essential for accurate and effective decoding of messenger RNAs. In Staphylococcus aureus, an additional constraint is imposed by the participation of tRNAGly isoacceptors in the addition of a pentaglycine side chain to cell-wall peptidoglycan precursors by transferases FmhB, FemA and FemB. Three tRNAGly isoacceptors poorly interacting with EF-Tu•GTP and the ribosome were previously identified. Here, we show that these ‘non-proteogenic’ tRNAs are preferentially recognized by FmhB based on kinetic analyses and on synthesis of stable aminoacyl-tRNA analogues acting as inhibitors. Synthesis of chimeric tRNAs and of helices mimicking the tRNA acceptor arms revealed that this discrimination involves identity determinants exclusively present in the D and T stems and loops of non-proteogenic tRNAs, which belong to an evolutionary lineage only present in the staphylococci. EF-Tu•GTP competitively inhibited FmhB by sequestration of ‘proteogenic’ aminoacyl-tRNAs in vitro. Together, these results indicate that competition for the Gly-tRNAGly pool is restricted by both limited recognition of non-proteogenic tRNAs by EF-Tu•GTP and limited recognition of proteogenic tRNAs by FmhB.

scholarly journals Two classes of EF1-family translational GTPases encoded by giant viruses

2019 ◽  
Vol 47 (11) ◽  
pp. 5761-5776
Author(s):  
Alexandra Zinoviev ◽  
Kazushige Kuroha ◽  
Tatyana V Pestova ◽  
Christopher U T Hellen
Keyword(s):  
Functional Characterization ◽  
Elongation Factor ◽  
Multiple Sequence ◽  
Translation Elongation ◽  
Trna Synthetases ◽  
Translation Apparatus ◽  
Giant Viruses ◽  
Termination Activity ◽  
A Site

Abstract Giant viruses have extraordinarily large dsDNA genomes, and exceptionally, they encode various components of the translation apparatus, including tRNAs, aminoacyl-tRNA synthetases and translation factors. Here, we focused on the elongation factor 1 (EF1) family of viral translational GTPases (trGTPases), using computational and functional approaches to shed light on their functions. Multiple sequence alignment indicated that these trGTPases clustered into two groups epitomized by members of Mimiviridae and Marseilleviridae, respectively. trGTPases in the first group were more closely related to GTP-binding protein 1 (GTPBP1), whereas trGTPases in the second group were closer to eEF1A, eRF3 and Hbs1. Functional characterization of representative GTPBP1-like trGTPases (encoded by Hirudovirus, Catovirus and Moumouvirus) using in vitro reconstitution revealed that they possess eEF1A-like activity and can deliver cognate aa-tRNAs to the ribosomal A site during translation elongation. By contrast, representative eEF1A/eRF3/Hbs1-like viral trGTPases, encoded by Marseillevirus and Lausannevirus, have eRF3-like termination activity and stimulate peptide release by eRF1. Our analysis identified specific aspects of the functioning of these viral trGTPases with eRF1 of human, amoebal and Marseillevirus origin.

scholarly journals Characterization of Alternaria Species Associated with Heart Rot of Pomegranate Fruit

2021 ◽  
Vol 7 (3) ◽  
pp. 172
Author(s):  
Francesco Aloi ◽  
Mario Riolo ◽  
Simona Marianna Sanzani ◽  
Annamaria Mincuzzi ◽  
Antonio Ippolito ◽  
...  
Keyword(s):  
Elongation Factor ◽  
Monomethyl Ether ◽  
Alternariol Monomethyl Ether ◽  
Translation Elongation ◽  
Microscopic Features ◽  
Alternaria Species ◽  
Rot Disease ◽  
Multigene Phylogenetic Analysis ◽  
Pomegranate Fruit

This study was aimed at identifying Alternaria species associated with heart rot disease of pomegranate fruit in southern Italy and characterizing their mycotoxigenic profile. A total of 42 Alternaria isolates were characterized. They were obtained from pomegranate fruits with symptoms of heart rot sampled in Apulia and Sicily and grouped into six distinct morphotypes based on macro- and microscopic features. According to multigene phylogenetic analysis, including internal transcribed spacer (ITS), translation elongation factor 1-α (EF-1α), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a SCAR marker (OPA10-2), 38 isolates of morphotypes 1 to 5 were identified as Alternaria alternata, while isolates of morphotype 6, all from Sicily, clustered within the Alternaria arborescens species complex. In particular, isolates of morphotype 1, the most numerous, clustered with the ex-type isolate of A. alternata, proving to belong to A. alternata. No difference in pathogenicity on pomegranate fruits was found between isolates of A. alternata and A. arborescens and among A. alternata isolates of different morphotypes. The toxigenic profile of isolates varied greatly: in vitro, all 42 isolates produced tenuazonic acid and most of them other mycotoxins, including alternariol, alternariol monomethyl ether, altenuene and tentoxin.

scholarly journals A genomic and proteomic analysis of surface proteins in bovine-adapted lineages of Staphylococcus aureus

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Shauna D. Drumm ◽  
Rebecca Owens ◽  
Jennifer Mitchell ◽  
Orla M. Keane
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Surface Proteins ◽  
Host Cells ◽  
Mass Spectrometry Analysis ◽  
In Vitro Assays ◽  
Immune Recognition ◽  
Independent Manner ◽  
Genes Encoding

In Ireland, Staphylococcus aureus is the most common cause of intramammary infection (IMI) in cattle with the bovine-adapted lineages CC151 and CC97 most commonly found. Surface proteins play a major role in establishing and maintaining the infection. A previous study revealed that a strain from the CC151 lineage showed significant decay in genes encoding predicted surface proteins. Twenty-three S. aureus strains, twelve belonging to CC151 and eleven belonging to CC97, isolated from clinical IMI, were sequenced and genes encoding cell wall anchored (CWA) proteins predicted. Analysis showed that a minority of genes encoding putative CWA proteins were intact in the CC151 strains compared to CC97. Of the 26 known CWA proteins in S. aureus, the CC151 strains only encoded 10 intact genes while CC97 encoded on average 18 genes. Also within the CC97 lineage, the repertoire of genes varied depending on individual strains, with strains encoding between 17-20 intact genes. Although CC151 is reported to internalize within bovine host cells, it does so in a fibronectin-binding protein (FnBPA and FnBPB) independent manner. In-vitro assays were performed and results showed that strains from CC151, and surprisingly also CC97, weakly bound bovine fibronectin and that the FnBPs were poorly expressed in both these lineages. Mass spectrometry analysis of cell wall extracts revealed that SdrE and AdsA were the most highly expressed CWA proteins in both lineages. These results demonstrate significant differences between CC151 and CC97 in their repertoire of genes encoding CWA proteins, which may impact immune recognition of these strains and their interactions with host cells.

Covalent Sortase A Inhibitor ML346 Prevents Staphylococcus aureus Infection of Galleria mellonella

2021 ◽  
Author(s):  
Xiang-Na Guan ◽  
Tao Zhang ◽  
Teng Yang ◽  
Ze Dong ◽  
Song Yang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Galleria Mellonella ◽  
Surface Proteins ◽  
Sortase A ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Aureus Infection ◽  
Cell Wall Peptidoglycan

The housekeeping sortase A (SrtA), a membrane-associated cysteine transpeptidase, is responsible for anchoring surface proteins to the cell wall peptidoglycan in Gram-positive bacteria. This process is essential for the regulation...

scholarly journals The Translation Elongation Factor eEF-1Bβ1 Is Involved in Cell Wall Biosynthesis and Plant Development in Arabidopsis thaliana

PLoS ONE ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. e30425 ◽  
Author(s):  
Zakir Hossain ◽  
Lisa Amyot ◽  
Brian McGarvey ◽  
Margaret Gruber ◽  
Jinwook Jung ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Plant Development ◽  
Elongation Factor ◽  
Cell Wall Biosynthesis ◽  
Translation Elongation Factor ◽  
Translation Elongation

THE MODE OF ACTION OF THE ANTIBIOTIC PAROMOMYCIN ON STAPHYLOCOCCUS AUREUS

1966 ◽  
Vol 12 (6) ◽  
pp. 1157-1165 ◽  
Author(s):  
A. von Seefried ◽  
D. C. Jordan
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Binding Sites ◽  
Bactericidal Action ◽  
Plate Method ◽  
Vitro Binding ◽  
Resistant Mutants ◽  
Intracellular Binding

Paromomycin (Humatin, Parke Davis & Co.), a broad-spectrum aminoglycosidic antibiotic, inhibits the incorporation of amino acids into the trypsinsoluble protein fraction of Staphylococcus aureus 257. Protein synthesis is inhibited immediately, but the synthesis of cell-wall mucopeptide and alcohol-soluble proteins and lipids is not affected for approximately 35 min after antibiotic addition to actively growing cells. Paromomycin, at the ribosomal level, prevents the attachment of amino acyl-s-RNA and causes accumulation of m-RNA.Divalent cations (Ca++ and Mg++) antagonize the bactericidal action of paromomycin and interfere with the in vivo binding of the antibiotic on both the cell surface and the intracellular binding sites. In vitro binding to free ribosomes can be prevented and reversed by both monovalent and divalent cations.Using a "cylinder-plate" method, involving the displacement of antibiotic from cellular fractions by 0.2 M MgCl2, the antibiotic can be recovered from the ribosomes, cytoplasm, and the cell wall of paromomycin-sensitive S. aureus cells, but is not found in any of these fractions isolated from paromomycin-resistant cells developed from the sensitive parent strain. The resistant mutants apparently have lost the ability to adsorb and transport the antibiotic into the cell.

scholarly journals Mapping the human translation elongation factor eEF1H complex using the yeast two-hybrid system

2002 ◽  
Vol 365 (3) ◽  
pp. 669-676 ◽  
Author(s):  
Francisco MANSILLA ◽  
Irene FRIIS ◽  
Mandana JADIDI ◽  
Karen M. NIELSEN ◽  
Brian F.C. CLARK ◽  
...  
Keyword(s):  
Elongation Factor ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Translation Elongation Factor ◽  
Yeast Two Hybrid ◽  
Translation Elongation ◽  
Guanine Nucleotide Exchange ◽  
Yeast Two Hybrid System ◽  
Two Hybrid

In eukaryotes, the eukaryotic translation elongation factor eEF1A responsible for transporting amino-acylated tRNA to the ribosome forms a higher-order complex, eEF1H, with its guanine-nucleotide-exchange factor eEF1B. In metazoans, eEF1B consists of three subunits: eEF1Bα, eEF1Bβ and eEF1Bγ. The first two subunits possess the nucleotide-exchange activity, whereas the role of the last remains poorly defined. In mammals, two active tissue-specific isoforms of eEF1A have been identified. The reason for this pattern of differential expression is unknown. Several models on the basis of in vitro experiments have been proposed for the macromolecular organization of the eEF1H complex. However, these models differ in various aspects. This might be due to the difficulties of handling, particularly the eEF1Bβ and eEF1Bγ subunits in vitro. Here, the human eEF1H complex is for the first time mapped using the yeast two-hybrid system, which is a powerful in vivo technique for analysing protein—protein interactions. The following complexes were observed: eEF1A1:eEF1Bα, eEF1A1:eEF1Bβ, eEF1Bβ:eEF1Bβ, eEF1Bα:eEF1Bγ, eEF1Bβ:eEF1Bγ and eEF1Bα:eEF1Bγ:eEF1Bβ, where the last was observed using a three-hybrid approach. Surprisingly, eEF1A2 showed no or only little affinity for the guanine-nucleotide-exchange factors. Truncated versions of the subunits of eEF1B were used to orientate these subunits within the resulting model. The model unit is a pentamer composed of two molecules of eEF1A, each interacting with either eEF1Bα or eEF1Bβ held together by eEF1Bγ. These units can dimerize via eEF1Bβ. Our model is compared with other models, and structural as well as functional aspects of the model are discussed.

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