Activators of54 -RNA polymerase holoenzyme couple ATP hydrolysis to formation of an open promoter complex. DctD ⌬1-142 , a truncated and constitutively active form of the 54 -dependent activator DctD from Sinorhizobium meliloti, displayed an altered DNase I footprint at its binding site located upstream of the dctA promoter in the presence of ATP. The altered footprint was not observed for a mutant protein with a substitution at or near the putative arginine finger, a conserved arginine residue thought to contact the nucleotide. These data suggest that structural changes in DctD ⌬1-142 during ATP hydrolysis can be detected by alterations in the DNase I footprint of the protein and may be communicated by interactions between bound nucleotide and the arginine finger. In addition, kinetic data for changes in fluorescence energy transfer upon binding of 2(3)-O-(N-methylanthraniloyl)-ATP (Mant-ATP) to DctD ⌬1-142 and DctD suggested that these proteins undergo multiple conformational changes following ATP binding.

People pay more attention to the security of RFID, this paper establishes the evaluation index architecture of RFID security, Then according to these indexes for the evaluation of the RFID system security which based on fuzzy synthetic evaluation model, all of this is to evaluate the security of RFID system.

By analyzing the security threats faced during the process of Internet data transfer, this paper compares the existing three security schemes, points out their limits and proposes a secure transfer protocol. This protocol can provide data confidentiality protection, data integrity protection, protection against replay attack and non-repudiation protection by ensuring the identities of both communication sides, and thus it ensures the security of data transmission of the Internet of things. This paper first introduces the overall framework of the protocol, then it elaborates the connection establishment and release process, data exchange process, key exchange process, finally it proves the feasibility of the protocol by the experiments.