NEAR‐ULTRAVIOLET MODIFICATION OF ESCHERICHIA COLI B UBIQUINONE IN VIVO AND IN VITRO*

Werbin, Harold; Lakchaura, B. D.; Jagger, John

doi:10.1111/j.1751-1097.1974.tb06519.x

Cited by 23 publications

(11 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, evidence of a more resistant form lies in the recent finding (Taber et al, 1978) that menaquinone appears to be a target molecule for near-UV-induced growth delay in Bacillus subtilis, a system requiring much higher fluences (several hundred kJ/m2), and probably utilizing a different mechanism, than in E. coli. wbiquinone-8 inactivation in E. coli not only has the wrbng action spectrum (Werbin et al, 1974), but also shows far too high an F,, (about 420 kJ/mz at 334 nm).] It is possible, therefore, that the far-UV inhibition of glycine transport i s due to some effect on a respira-tory protein, while the near-UV part is due to an effect on a relatively near-UV-resistant form of menaquinone, which might function as a cofactor for that protein.…”

Section: Action Spectrummentioning

confidence: 99%

ULTRAVIOLET ACTION SPECTRUM (238–405 nm) FOR INHIBITION OF GLYCINE UPTAKE IN E. COLI*

Ascenzi

Jagger

1979

Photochem & Photobiology

Self Cite

View full text Add to dashboard Cite

Abstract— Initial rate of uptake of 3H‐glycine by Escherichia coli B/r was measured immediately after irradiation with monochromatic light. Uptake was proportional to time for at least 2 min in both control and irradiated samples. Inhibition of uptake is an exponential function of fluence to about 20% remaining activity, beyond which it is much more resistant to irradiation, suggesting two different uptake systems. The principal (sensitive) system shows an F37 of 2.2 kJ/m2 at 280 nm and 110 kJ/m2 at 334 nm. The response is independent of cell killing and of presence of the rel gene. The chromophore remains unidentified, although an action spectrum suggests a protein chromophore in the far‐UV (below 300 nm) region and a menaquinone chromophore in the near‐ultraviolet (above 300 nm). A 10–20%, stimulation of uptake rate, which we cannot account for, is observed at low fluences (generally below 100 kJ/m2) at 313, 366 and 405 nm, but not at 334 nm.

show abstract

Section: Action Spectrummentioning

confidence: 99%

ULTRAVIOLET ACTION SPECTRUM (238–405 nm) FOR INHIBITION OF GLYCINE UPTAKE IN E. COLI*

Ascenzi

Jagger

1979

Photochem & Photobiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recent experiments on inactivation of ubiquinone Q-8 (a benzoquinone) in uiuo show it is not a likely chromophore. either in terms of the absorption spectrum or the fluences required for inactivation (Werbin et a/., 1974). Vitamin K2 (a naphthoquinone) has a more suitable absorption spectrum, but its fit to the action spectra for either inhibition of RNA synthesis or growth delay is not as good as that of tRNA, especially with respect to the wavelength for maximum effect (Fig.…”

Section: Other Chromophoresmentioning

confidence: 99%

EFFECTS OF NEAR‐ULTRAVIOLET and VIOLET RADIATIONS (313–405 NM) ON DNA, RNA, and PROTEIN SYNTHESIS IN E. COLI B/r: IMPLICATIONS FOR GROWTH DELAY*

Ramabhadran

1975

Photochem & Photobiology

View full text Add to dashboard Cite

Fluences (21-32 kJ/m2) of near-ultraviolet radiation that induce about a 1-h growth delay in continuously growing cultures of E. coli B/r are found to produce complete cessation of net RNA synthesis, while the effects on protein and DNA synthesis are considerably milder. The near-UV action spectrum for this inhibition of RNA synthesis is similar to the action spectrum for growth delay in E. coli B and to the absorption spectrum of E. coli valyl transfer RNA. In addition, the fluences required for inhibition of RNA synthesis and for growth delay are similar to those reported for formation of 4-thiouridine-cytidine adducts in transfer RNA. These findings suggest that the chromophore and target for near-UV-induced inhibition of both net RNA synthesis and growth in E. coli may be 4-thiouridine in transfer RNA.

show abstract

“…Bacterial studies have shown that growth delay has a narrow action spectrum, peaking at 340 nm. Earlier suggestions that quinones might be the chromophores and oxidative phosphorylation the cellular target (1) have not been supported by recent work showing that coenzyme Q is resistant to near-UV radiation in vivo (3) and that ATP synthesis shows a threshold response (B. Lakchaura, T. Fossum, and J. Jagger, J. Bacteriol., 125, in press).…”

mentioning

confidence: 99%

Mechanism of growth delay induced in Escherichia coli by near ultraviolet radiation.

Ramabhadran¹,

Jagger²

1976

Proc. Natl. Acad. Sci. U.S.A.

135

View full text Add to dashboard Cite

Continuously growing cultures of E. coli B/r were irradiated with a fluence of broad-band near-ultraviolet radiation (315-405 nm) sufficient to cause extensive growth delay and complete cessation of net RNA synthesis. Chloramphenicol treatment was found to stimulate resumption of RNA synthesis, similar to that observed with chloramphenicol treatment after amino-acid starvation. E. coli strains in which amino-acid starvation does not result in cessation of RNA synthesis ("relaxed" or ret strains) show no cessation of growth and only a slight effect on the rate of growth or of RNA synthesis. These findings show that such near-UV fluences do not inactivate the RNA synthetic machinery but affect the regulation of RNA synthesis, in a manner similar to that produced by amino-acid starvation. Such regulation is believed to be mediated through alterations in concentration of guanosine tetraphosphate (ppGpp), and our estimations of ppGpp after near-UV irradiation are consistent with such an interpretation. These data, combined with earlier published data, strongly suggest that the mechanism of near-UV-induced growth delay in E. coil involves partial inactivation of certain tRNA species, which is interpreted by the cell in a manner similar to that of amino-acid starvation, causing a rise in ppGpp levels, a shut-off of net RNA synthesis, and the induction of a growth delay.Near-ultraviolet radiation (near-UV; 300-380 nm) is present in sunlight, but is absorbed only marginally, if at all, by proteins and nucleic acids. Yet the well-known deleterious effects of far-ultraviolet radiation (far-UV; below 300 nm), such as killing, induction of mutation, and inhibition of growth, are found to occur in bacteria throughout the near-UV region (1, 2).Of these effects, the one induced by the lowest fluences of near UV is the inhibition of growth*. Bacterial studies have shown that growth delay has a narrow action spectrum, peaking at 340 nm. Earlier suggestions that quinones might be the chromophores and oxidative phosphorylation the cellular target (1) have not been supported by recent work showing that coenzyme Q is resistant to near-UV radiation in vivo (3) and that ATP synthesis shows a threshold response (B. Lakchaura, T. Fossum, and J. Jagger, J. Bacteriol., 125, in press). In addition, it is unlikely that DNA is the target for near-UV-induced growth inhibition (4).Inhibition of growth clearly must involve inhibition of macromolecular synthesis. Swenson et al. (5) He has also shown that the action spectrum for induction of this inhibition of RNA synthesis is similar to the action spectrum for induction of growth delay in E. coli, and that the growth delay action spectrum fits very closely to the absorption spectrum of tRNAs that contain the unusual nucleoside 4-thiouridine (4Srd). It is known that near-UV irradiation in vitro of such tRNAs can induce an adduct between the 4Srd in the 8-position and a cytidine in the 13-position of the tRNA, and that this lowers the rate at which the tRNA accepts amino acids (7). The f...

show abstract

NEAR‐ULTRAVIOLET MODIFICATION OF ESCHERICHIA COLI B UBIQUINONE IN VIVO AND *IN VITRO**

Cited by 23 publications

References 31 publications

ULTRAVIOLET ACTION SPECTRUM (238–405 nm) FOR INHIBITION OF GLYCINE UPTAKE IN E. COLI*

ULTRAVIOLET ACTION SPECTRUM (238–405 nm) FOR INHIBITION OF GLYCINE UPTAKE IN E. COLI*

EFFECTS OF NEAR‐ULTRAVIOLET and VIOLET RADIATIONS (313–405 NM) ON DNA, RNA, and PROTEIN SYNTHESIS IN E. COLI B/r: IMPLICATIONS FOR GROWTH DELAY*

Mechanism of growth delay induced in Escherichia coli by near ultraviolet radiation.

Contact Info

Product

Resources

About