ISOLATION OF RHODOBACTER-CAPSULATUS TRANSKETOLASE - CLONING AND SEQUENCING OF ITS STRUCTURAL TKTA GENE

Rhodobacter capsulatus transketolase (Tkt) protein has been isolated f rom strain B10 by heparin affinity chromatography. Oligodeoxyribonucle otides (oligo) constructed as based on the amino-acid sequences were u sed for polymerase chain reaction (PCR) amplification on total genomic DNA. Southern hybridization with the PCR product as a probe allowed t he isolation of a 5-kb PstI DNA fragment containing the structural Tkt -encoding gene (tktA) which was cloned and sequenced. The deduced tktA product of 671 aa (72815 Da) shares 59% identity with Rhodobacter sph aeroides Tkt.