CLONING, SEQUENCING AND EXPRESSION OF THE GENE ENCODING 2-PHOSPHOGLYCERATE KINASE FROM METHANOTHERMUS-FERVIDUS

The gene encoding 2-phosphoglycerate kinase (2PGK), which catalyses th e first step in the biosynthesis of cyclic 2,3-diphosphoglycerate in m ethanogens, was cloned and sequenced from the hyperthermophilic Methan othermus fervidus. The 2pgk gene codes for 304 amino acids, correspond ing to a relative molecular mass of 35040. The 2pgk mRNA was estimated to be 1600 nucleotides in size. Putative transcription signals and th e ribosome-binding site of 2pgk are discussed. Production of 2PGK from M. fervidus in Es-cherichia coli reveals the same apparent molecular weights for the native enzyme and its denatured subunit as those shown by the 2PGK purified from M. feruidus, Also the kinetic parameters of 2PKG produced in E. coli correspond well with those from the enzyme i solated from the natural host M. fervidus.