Complex Detection Between Transcription Regulator and Promoter DNA by UV Spectroscopic Method

Abstract

UV spectrophotometer was used to detect protein-DNA complex from DNA melting profile under constant temperature increase. Melting temperature (Tm) was 43℃ in copA duplex DNA alone. In the presence of Proteus mirabilis transcription regulator protein (PMTR) protein at 0.2 and 0.4 μM, Tm’s were 45 ± 0.5 and 47.6 ± 0.6oC, respectively. According to fluorescence polarization and gel shift assay. PMTR:copA complex was detected by the retarded migration on gel and the dissociation constant (K_d) was (9.2 ± 2.8) × 10^(-9) M.