In this work we have identified the cagntR gene, present between the nrdE and nrdF genes of Corynebacterium ammoniagenes, as a transcriptional regulator belonging to the GntR family. This gene encodes a transcriptional factor actively transcribed in the opposite direction relative to the nrdHIEF operon. It is expressed in a cell-culture-dependent fashion and, although the members of this family have been reported to regulate transcription of genes found within their vicinity, we have shown that cagntR is not involved in the transcriptional regulation of either nrdE or nrdF. The role of this regulator, however, remains unknown.