Biopolymers and cell. 2000; 16 (5): 403 - 408

Replacement of groEL gene of Escherictiia coll by its homologue from Sinorhizobium meliloti

V. N. Yerko, P. A. Lund

We show that groEL gene from S. meliloti coding for chaperonin's subunits with molecular weight 60 kDa complements deletion of groEL gene of E. coli accomplished by replacement of groEL by nptll gene using PI phage transduction. For expression of groEL gene from S. meliloti in E. coli cells we used plasmid with E. coli arabinose promoter allowing tight regulation of chaperonin biosynthesis by varying concentration of arabinose and glucose in growth medium. The method of replacement of chromosomal groEL gene by heterologous groEL allows investigation of chaperonin's behavior in a cell that does not carry additionally temperature sensitive chaperonins and thus allows to avoid undesirable interaction of chaperonins of differen origin and inclusion of heterologous subunits into the same chaperonin.