Resistance of lambda cI translation to antibiotics that inhibit translation initiation

Abstract

The lambda cI lysogenic transcript is unusual in having no leader. Expression of a cI-lacZ protein fusion was relatively resistant to kasugamycin and pactamycin, which inhibit translation initiation on transcripts with leaders. Our data imply that there are distinct differences in translation initiation between the two classes of transcripts.

Antibiotics and the Inhibition of Ribosome Function

“…Ksg does not inhibit translation of leaderless mRNAs at concentrations where translation of canonical mRNAs is abolished [16,17]. (Canonical mRNAs in prokaryotes are those mRNAs that contain an AUG start codon, upstream of which, is the socalled Shine and Dalgarno (SD) sequence, a region of the mRNA complementary to part of the 3Ј-end of the 16S rRNA called the anti-SD.…”

“…16 Spectinomycin binding site on the 30S subunit. (A) Overview of the spectinomycin binding site on the 30S subunit (pdb 1fjg[67]).…”

Specific, efficient, and selective inhibition of prokaryotic translation initiation by a novel peptide antibiotic

“…Kasugamycin binds to the 30S subunit (and 70S ribosomes) with K d ϭ 2 ϫ 10 Ϫ5 M and is reported to enhance accuracy of protein synthesis (29) and to inhibit the initiation phase of translation without affecting elongation (30,31), but unlike GE81112 (Fig. 2D), kasugamycin does not inhibit leaderless mRNA translation (32,33). Kasugamycin was reported to destabilize 30S (but not 70S) initiation complexes, from which it removes prebound fMet-tRNA (34), but under our experimental conditions, kasugamycin inhibits prokaryotic protein synthesis with IC 50 Ϸ 30 M, a value that is Ϸ40 times higher than that of GE81112 (Fig.…”

An Escherichia coli Strain Producing a Leaderless mRNA from the Chromosomal lac Promoter

“…The mechanisms of leaderless mRNA translation in E. coli have so far been studied using either in vitro techniques [6][7][8][9] or in vivo approaches based on plasmid constructs bearing the translationally fused genes like Ò I -lacZ [10][11][12][13][14]. The results of these studies revealed interesting peculiarities of the leaderless mRNA translation, such as capability of the initiation complex formation with nondissociated 70S ribosomes in vitro [6][7][8][9][10], an enhanced translation level in vivo in the presence of chromosomal mutations in the rpsB gene encoding ribosomal protein S2 [11], and the resistance to antibiotic kasugamycin [8,12].…”