Binding of the IclR-type regulator HutR in the histidine utilization (hut) gene cluster of the human pathogen Corynebacterium resistens DSM 45100

Abstract

The genome of the human pathogen Corynebacterium resistens DSM 45100 is equipped with a histidine utilization (hut) gene cluster encoding a four‐step pathway for the catabolism of l‐histidine and a transcriptional regulator of the IclR superfamily, now named HutR. The utilization of l‐histidine might be relevant for the growth of C. resistens in its natural habitat, probably the histidine‐rich inguinal and perineal areas of the human body. The ability of C. resistens to utilize l‐histidine as a sole source of nitrogen was demonstrated by growth assays in synthetic minimal media. Reverse transcriptase PCRs revealed enhanced transcript levels of the hut genes in C. resistens cells grown in the presence of l‐histidine. Promoter‐probe assays showed that the hut genes are organized in three transcription units: hutHUI, hutR, and hutG. The respective transcriptional start sites were mapped by 5′ RACE‐PCR to detected putative promoter regions. DNA band shift assays with purified HutR protein identified the 14‐bp DNA sequence TCTGwwATwCCAGA located upstream of the mapped promoters. This DNA motif includes a 4‐bp terminal palindrome, which turned out to be essential for HutR binding in vitro. These data add a new physiological function to the large IclR family of transcriptional regulators.

Structural and functional characterization of Rv0792c from Mycobacterium tuberculosis: identifying small molecule inhibitors against GntR protein

“…As Rv0792c belongs to the HutC family of GntR regulators, we next evaluated if L-histidine or urocanic acid (urocanic acid is an intermediate in the L-histidine catabolism) acts as effectors and alter the DNA binding ability of Rv0792c. Contrary to previous reports, we observed that the DNA binding ability of Rv0792c is not affected in the presence of L-histidine and urocanic acid (data not shown) (52)(53)(54)(55). In order to identify Rv0792c effector molecules, ALISA was performed in the presence of various ligands.…”

Identification of New Genes Contributing to the Extreme Radioresistance of Deinococcus radiodurans Using a Tn5-Based Transposon Mutant Library

“…radiodurans hut operon shows similarity to those of Corynebacterium resistens with an adjacent gene encoding a transcription regulator of the IclR family ( DRA0152 ), and this IclR factor has been shown to activate the hut operon in C . resistens [ 75 ], suggesting a similar regulation of the Hut system in both organisms.…”

The Family Corynebacteriaceae

“…However, systematic growth assays with Corynebacterium resistens revealed a cysteine auxotrophy (Schröder et al 2012c), despite the presence of all genes of the cysteine biosynthesis pathway (Schröder et al 2012a). Most, if not all, Corynebacterium species are auxotrophic for the vitamin biotin due to the lack of a varying number of genes involved in the biotin biosynthesis pathway .…”