中国生物工程杂志

DEK protein’s carboxyterminal DNAbinding region (CBD) is a newly found DNAbinding domain of DEK,which contains several phosphorylation sites and has a close correlation with DEK protein's function in vivo and in vitro.Using prokaryotic expression system,the peptide of DEK protein's carboxyterminal DNAbinding region (CDB) was expressed and purified.In detail,the CDB DNA fragment was constructed into pET30a (+) vector,and E.coli BL21 (DE3) competent cells were used as host cells.The fusion protein HisCBD was expressed by induction of IPTG and purified by NiNTA agarose.The result of SDSPAGE showed that the molecular weight of the purified protein was about 10.7kDa.Electrophoretic mobility shift assay (EMSA) indicated that DEKCDB prefered to bind to supercoiled form of DNA in vitro,it had similar character to the binding of whole length DEK protein with DNA.This suggested that the carboxyterminal DNAbinding region of DEK protein might function on the binding of DEK protein to DNA partly.