Member of the two-component regulatory system CrdR/CrdS that induces the transcriptional induction of the copper resistance determinant CrdA in response to increasing concentrations of copper ions (PubMed:15968080). Functions as a sensor protein kinase that phosphorylates CrdR (Probable). In turn, CrdR functions as a transcriptional regulator by direct binding to promoter regions of target genes including the crdA promoter or nitric oxide-responsive gene promoters (PubMed:26082024). ATP + protein L-histidine = ADP + protein N-phospho-L-histidine. Deletion mutant is not able to colonize the stomach in mice (PubMed:12933888). It shows also a significant loss of viability upon exposure to nitric oxide (PubMed:26082024).