EXPRESSION OF SULFOLOBUS-SOLFATARICUS TRPE AND TRPG GENES IN ESCHERICHIA-COLI

The genes trpE and trpG of the hyperthermophilic archaeon Sulfolobus s olfataricus, encoding the components I and II of anthranilate synthase , were cloned and co-expressed in Escherichia coli. The properties of the recombinant protein were determined and compared to those of the w ild type complex. Gel filtration chromatography revealed an alpha(2) b eta(2) composition. The heteromeric enzyme is fully active above 85 de grees C and can be considered to be an ''extremozyme'' according to Ad ams et al.[1]. Sulfolobus solfataricus anthranilate synthase is subjec t to feedback inhibition by L-tryptophan even if it lacks the co-opera tivity that has been observed for all the other tetrameric anthranilat e synthases. (C) 1997 Academic Press