A segment of Myxococcus xanthus ops DNA functions as an upstream activation site for tps gene transcription

Abstract

A segment of DNA located between 131 and 311 base pairs (bp) upstream from the transcriptional start of the Myxococcus xanthus ops gene (-131 to -311) was shown to function as an upstream activation site (UAS) for developmentally regulated transcription from the tps gene promoter region. The activation of early developmental transcription by the ops UAS was independent of orientation and could be increased by the addition of a second copy of the UAS. The ops UAS segment continued to function when placed 1.5 kbp upstream from the transcription initiation site. DNA from the tps promoter region was required for transcriptional activation by the ops UAS, and a specific requirement for the sequence of tps DNA between -34 and -66 was demonstrated. Several specific ops UAS DNA-protein complexes were observed after incubation of this DNA segment with an extract of early developmental M. xanthus cells. Extracts of vegetative cells contained much less ops UAS-specific DNA-binding activity. When the distance between the tps and ops genes was increased from 2 to 15 kbp by insertion of a transduced segment of DNA, the amount of developmentally induced tps RNA was found to be about one-third that found in wild-type M. xanthus. Our observations suggest that the regulatory region of the ops gene functions not only to control ops gene expression but also to increase early developmental expression of the tps gene located about 2 kbp downstream on the M. xanthus chromosome.

Characterization of the regulatory region of a cell interaction-dependent gene in Myxococcus xanthus

“…All such genes examined so far exhibit this requirement (14,24). In some cases, multiple elements appear to act over distances of several kilobases from the transcriptional start site (37). In the case of ⍀4403, however, our results show that 80 bp of DNA upstream of the transcriptional start site (Fig.…”

Expression of the psbDII gene in Synechococcus sp. strain PCC 7942 requires sequences downstream of the transcription start site

“…The +11 to +84 regulatory region of the psbDII gene may comprise three or more cis-acting regulatory elements that function either independently or synergistically. Such a scheme has been proposed for gene regulation in mammalian and yeast cells (24), for genes induced by oxidative stress (oxyR, katG, and ahpC) in E. coli (46), and for the developmentally expressed tps and ops genes in Myxococcus xanthus (10,20). The results reported here do not specify the mechanism of psbDII regulation by light, but viable possibilities are that control is mediated by the promoter-distal binding site or that induction is achieved through structural changes in proteins already bound to the DNA.…”

Regulation of dev , an Operon That Includes Genes Essential for Myxococcus xanthus Development and CRISPR-Associated Genes and Repeats

“…One of these is located more than 535 bp upstream of the TSS, an unusually long distance for a positive cis-regulatory element in bacteria. However, in M. xanthus, activity of the tps (42), csgA (58), ⍀4499 (15), and ⍀4514 (26) promoters has been shown to depend on sequences located more than 500 bp upstream of the TSS. These sequences have been inferred to be binding sites for transcriptional activators and are typically located in the coding region of an upstream gene, based on our analysis of the M. xanthus genome sequence (20).…”