Bacillus Megaterium Heat Shock System Cloning And Operon Analysis

Class I heat shock genes,hrcA-grpE-dnaK-dnaJ and groES-groEL were cloned from Bacillus megaterium RF5 on the bases of reported sequence of dnaK gene of the same species and groES-groEL genes of Bacillus subtilis,hrcA,grpE,dnaJ,groES and groEL were first time sequenced,and the gene products were 60%,63%,81%, 90%and 91%identity to their homologs of B.subtilis.Aσ^A-type promoter of gram-positive bacteria(P_A1)and a terminator were located upstream of the hrcA and downstream of dnaK,and a controlling inverted repeat of chaperone expression element(CIRCE)was identified between P_A1and hrcA.Anotherσ_A-type promoter (P_A2)and a terminator were found upstream and downstream of dnaJ,indicating that B.megaterium has a dnaK operon followed by a transcription unit containing a single gene,dnaJ.The structure of dnaJ transcription unit is the same to that found in Listeria monocytogenes rather than those in other species of Bacillus.