Similarities in the structure of the transcriptional repressor AmtR in two different space groups suggest a model for the interaction with GlnK.

AmtR belongs to the TetR family of transcription regulators and is a global nitrogen regulator that is induced under nitrogen-starvation conditions in Corynebacterium glutamicum. AmtR regulates the expression of transporters and enzymes for the assimilation of ammonium and alternative nitrogen sources, for example urea, amino acids etc. The recognition of operator DNA by homodimeric AmtR is not regulated by small-molecule effectors as in other TetR-family members but by a trimeric adenylylated P-type signal transduction protein named GlnK.

Colonization of human epithelial cell lines by Corynebacterium ulcerans from human and animal sources.

Corynebacterium ulcerans is an emerging pathogen transmitted by a zoonotic pathway to humans. Despite rising numbers of infections and potentially fatal outcomes, data on the colonization of the human host are lacking up to now. In this study, adhesion of two C.

Induction of the NFκ-B signal transduction pathway in response to Corynebacterium diphtheriae infection.

Corynebacterium diphtheriae, the causative agent of diphtheria, has been thoroughly studied with respect to toxin production and pili formation, while knowledge on host responses to C. diphtheriae infection is limited. In this study, we studied adhesion to and invasion of epithelial cells by different C.

Adaptation of AmtR-controlled gene expression by modulation of AmtR binding activity in Corynebacterium glutamicum.

In corynebacteria, nitrogen regulation is controlled by the TetR family protein AmtR, which was extensively studied in the last years. In frame of these studies a number of AmtR binding sites were identified and characterized and it became obvious that for distinct genes the number and sequences of these sites varied significantly. In this study, the influence of numbers and alterations of AmtR binding sites were addressed by in vivo and in vitro studies.

Crystallization and preliminary crystallographic analysis of the global nitrogen regulator AmtR from Corynebacterium glutamicum.

AmtR, a member of the TetR family of transcription regulators, is a global regulator of nitrogen control in Corynebacterium glutamicum. Unlike other TetR-family members, which are regulated by small-molecule effectors, AmtR is regulated by a protein called GlnK. It has been shown that a GlnK trimer has to become adenylylated prior to formation of a complex with AmtR.

DNA binding by Corynebacterium glutamicum TetR-type transcription regulator AmtR.

Background: The TetR family member AmtR is the central regulator of nitrogen starvation response in Corynebacterium glutamicum. While the AmtR regulon was physiologically characterized in great detail up to now, mechanistic questions of AmtR binding were not addressed. This study presents a characterization of functionally important amino acids in the DNA binding domain of AmtR and of crucial nucleotides in the AmtR recognition motif.

Nitrogen control in Mycobacterium smegmatis: nitrogen-dependent expression of ammonium transport and assimilation proteins depends on the OmpR-type regulator GlnR.

The effect of nitrogen regulation on the level of transcriptional control has been investigated in a variety of bacteria, such as Bacillus subtilis, Corynebacterium glutamicum, Escherichia coli, and Streptomyces coelicolor; however, until now there have been no data for mycobacteria. In this study, we found that the OmpR-type regulator protein GlnR controls nitrogen-dependent transcription regulation in Mycobacterium smegmatis. Based on RNA hybridization experiments with a wild-type strain and a corresponding mutant strain, real-time reverse transcription-PCR analyses, and DNA binding studies using cell extract and purified protein, the glnA (msmeg_4290) gene, which codes for glutamine synthetase, and the amtB (msmeg_2425) and amt1 (msmeg_6259) genes, which encode ammonium permeases, are controlled by GlnR.