The oligomerization of CynR in Escherichia coli

Deletion analysis and alanine‐scanning based on a homology‐based interaction model were used to identify determinants of oligomerization in the transcriptional regulator CynR, a member of the LysR‐type transcriptional regulator (LTTR) family. Deletion analysis confirmed that the putative regulatory domain of CynR was essential for driving the oligomerization of λ repressor‐CynR fusion proteins. The interaction surface of a different LTTR and OxyR was mapped onto a multiple sequence alignment of the LTTR family. This mapping identified putative contacts in the CynR regulatory domain dimer interface, which were targeted for alanine‐scanning mutagenesis. Oligomerization was assayed by the ability of mutant λ repressor‐CynR fusions to assemble in E. coli revealing interesting similarities and differences between OxyR and CynR.