Mikhail Gelfand has become the last author of the paper “Evolution of transcriptional regulation of histidine metabolism in Gram-positive bacteria” that has been recently published in BMC Genomics journal. In the previous work, the authors described a novel DNA-binding transcription factor (named HisR) that controls the histidine metabolism genes in diverse Gram-positive bacteria from the Firmicutes phylum. In the current paper, the scientists report the identification of HisR-binding sites within the regulatory regions of the histidine metabolism and transport genes in 395 genomes representing the Bacilli, Clostridia, Negativicutes, and Tissierellia classes of Firmicutes, as well as in 97 other HisR-encoding genomes from the Actinobacteria, Proteobacteria, and Synergistetes phyla. Using systematical analysis of the upstream regions of genes controlled by HisR, the researchers identified many regulatory elements that control genes involved in histidine transport and metabolism. Full text of the paper is available here.