Abstract
Thioredoxin (Trx) is small ubiquitous protein that catalyzes thiol-disulfide reaction by two catalytic cysteine. Green sulfur bacterium Chlorobium tepidum TLS require strict anaerobic condition for growth and use various inorganic sulfur compounds as well as H2S as electron donors. The complete genome of C. tepidum was determined in 2002 (The Institute for Genomic Research) and two Trx homologues were found. To elucidate Trx system in C. tepidum, we constructed recombinant Trx expression vector and cysteine mutant which one cysteine at the active site was substituted with serine. By immobilized cysteine mutant to resin, Trx target protein of C. tepidum were efficiently acquired.
