ENHANCED READTHROUGH OF OPAL (UGA) STOP CODONS AND PRODUCTION OF MYCOPLASMA-PNEUMONIAE P1 EPITOPES IN ESCHERICHIA-COLI

Expression of mycoplasma sequences in Escherichia coli is often hinder ed by an unusual mycoplasmal codon usage pattern: the UGA stop codon i s utilized for tryptophan. This may result in the truncation of cloned proteins and may prevent the detection of products of many cloned gen es. To circumvent this translation barrier, we have developed an expre ssion system for the production of mycoplasma proteins in E. coli. The efficiency of an opal suppressor tRNA (trp T176) was augmented with o ther suppressor mutations {prfB3 or rrsB(SuUGA-DELTAC1054)} which infl uence termination events. System efficacy was analyzed by employing su ppressor mutations in the expression of TGA-containing sequences from the PI protein-encoding gene of Mycoplasma pneumoniae.