Kirromycin‐resistant elongation factor Tu from wild‐type of <i>Lactobacillus brevis</i>

Wörner, Walter; Wolf, H.

doi:10.1016/0014-5793(82)80944-7

Cited by 14 publications

(5 citation statements)

References 17 publications

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“…Resistance mechanism 1: obstruction of kirromycin binding to EF-Tu.GTP This barrier mechanism has been proposed earlier following measurements of a lower affinity of kirromycinresistant EF-Tu-GTP for the antibiotic (Fasano and Parmeggiani, 1981;van der Meide et al, 1981;Worner and Wolf, 1982), and is confirmed by our data in Table I. Our crystallographic data are compatible with this mechanism since an alignment of all three positions in the domain 1-3 interface of EF-Tu-GTP was found (Figures 8 and 9). This strongly indicates that the mutations obstruct kirromycin binding by altering the interface.…”

Section: Discussionsupporting

confidence: 91%

The structural and functional basis for the kirromycin resistance of mutant EF-Tu species in Escherichia coli.

et al. 1994

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A structural and functional understanding of resistance to the antibiotic kirromycin in Escherichia coli has been sought in order to shed new light on the functioning of the bacterial elongation factor Tu (EF‐Tu), in particular its ability to act as a molecular switch. The mutant EF‐Tu species G316D, A375T, A375V and Q124K, isolated by M13mp phage‐mediated targeted mutagenesis, were studied. In this order the mutant EF‐Tu species showed increasing resistance to the antibiotic as measured by poly(U)‐directed poly(Phe) synthesis and intrinsic GTPase activities. The K'd values for kirromycin binding to mutant EF‐Tu.GTP and EF‐Tu.GDP increased in the same order. All mutation sites cluster in the interface of domains 1 and 3 of EF‐Tu.GTP, not in that of EF‐Tu.GDP. Evidence is presented that kirromycin binds to this interface of wild‐type EF‐Tu.GTP, thereby jamming the conformational switch of EF‐Tu upon GTP hydrolysis. We conclude that the mutations result in two separate mechanisms of resistance to kirromycin. The first inhibits access of the antibiotic to its binding site on EF‐Tu.GTP. A second mechanism exists on the ribosome, when mutant EF‐Tu species release kirromycin and polypeptide chain elongation continues.

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Section: Discussionsupporting

confidence: 91%

The structural and functional basis for the kirromycin resistance of mutant EF-Tu species in Escherichia coli.

et al. 1994

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“…Studies on other Gram-positive bacteria (Staphylococcus aureus, lactobacilli) demonstrate that, in most cases, kirromycin resistance is mediated by EF-Tu (Hall et al, 1989;Woerner & Wolf, 1982;Woemer et al, 1983), whereas in E. coli resistance is due to lack of penetration into the cell. Although the tuf genes, which encode EF-Tu, appear to be highly conserved among bacteria (Filer & Furano, 1980), the kirromycin-binding site may be less conserved than other domains of the protein.…”

Section: Discussionmentioning

confidence: 99%

Inhibition of bacterial protein synthesis by elongation-factor-Tu-binding antibiotics MDL 62,879 and efrotomycin

Landini¹,

Bandera²,

Goldstein³

et al. 1992

Biochemical Journal

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MDL 62,879 (formerly GE 2270 A) is a novel antibiotic active against Gram-positive bacteria by inhibiting protein synthesis. MDL 62,879 is not active against Gram-negative bacteria, but inhibits cell-free protein synthesis in extracts from Escherichia coli, and shows a high binding affinity for its elongation factor Tu (EF-Tu). We prepared ribosomes and protein-synthesis elongation factors from three sources: E. coli, Bacillus subtilis, and a strain of B. subtilis selected for resistance to MDL 62,879 (strain G1674). Homologous and heterologous reconstituted systems were used to compare the effects of MDL 62,879 and of efrotomycin, an EF-Tu inhibitor of the kirromycin class, which is inactive against both B. subtilis and E. coli. We showed that in cell-free protein synthesis: (a) E. coli was sensitive to both MDL 62,879 and efrotomycin; (b) B. subtilis was sensitive to MDL 62,879, but not to efrotomycin; (c) B. subtilis G1674 was resistant to both antibiotics. In the E. coli system and in the system from wild-type B. subtilis, inhibition by MDL 62,879 was reversed upon addition of purified EF-Tu from B. subtilis G1674. This demonstrates that the antibiotic acts by inhibition of EF-Tu. In contrast, extracts from B. subtilis failed to restore activity in an efrotomycin-inhibited E. coli system. Dominance or resistance to MDL 62,879 and of sensitivity to efrotomycin in heterologous cell-free protein synthesis confirms that inhibition of EF-Tu by the two antibiotics is mediated by different mechanisms of action.

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“…On the basis of these studies with E. hirae and previous studies with other gram-positive bacteria (7,9,10,16,20,21), it appears that resistance or susceptibility to elfamycins in enterococci is mediated by EF-Tu. Although this protein is considered to be highly conserved among eubacteria (3,11), the elfamycin-binding site appears to be less conserved than other portions of the molecule (10).…”

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confidence: 73%

“…Among gram-positive species, susceptibility or resistance to elfamycins appears to be determined, instead, by the properties of the EF-Tu's of the organisms. Staphylococci and some species of lactobacilli and Bacillus are resistant to elfamycins (7,9,16,20,21), and resistance has been reported, but not extensively studied, among enterococci (14). We report on the susceptibility patterns of enterococci to elfamycins and on the potential use for these antibiotics as an aid to identification to the species level.…”

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confidence: 97%

Differential susceptibilities of enterococcal species to elfamycin antibiotics

Miele¹,

Goldstein²,

Bandera³

et al. 1994

J Clin Microbiol

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The elfamycins are a class of naturally occurring antibiotics not currently used in the therapy of human disease. Enterococcus faecium and closely related species (Enterococcus durans and Enterococcus hirae) are susceptible to these antibiotics, while isolates of Enterococcusfaecalis and other enterococcal species are highly resistant. Among enterococci, susceptibility or resistance to elfamycins appears to be determined by the bacterial protein synthesis elongation factor EF-Tu. Elfamycin susceptibility may be a useful adjunct for rapidly distinguishing E. faecalis and E. faecium in the clinical microbiology laboratory and/or as a supplementary test for use in determining the species of enterococci.

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Kirromycin‐resistant elongation factor Tu from wild‐type of Lactobacillus brevis

Cited by 14 publications

References 17 publications

The structural and functional basis for the kirromycin resistance of mutant EF-Tu species in Escherichia coli.

The structural and functional basis for the kirromycin resistance of mutant EF-Tu species in Escherichia coli.

Inhibition of bacterial protein synthesis by elongation-factor-Tu-binding antibiotics MDL 62,879 and efrotomycin

Differential susceptibilities of enterococcal species to elfamycin antibiotics

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