Thioredoxin-thioredoxin reductase system of Streptomyces clavuligerus: sequences, expression, and organization of the genes

DNA sequences of Streptomyces clavuligerus were determined by cloning the genes that encode thioredoxin and thioredoxin reductase of the bacterium. Thioredoxin reductase is seen as a 35-KDa protein, sharing an amino acid sequence with Escherichia coli, while thioredoxin is a 12-KDA protein, with an amino acid sequence similar to other thioredoxins. The cysternem redox-active segment is found in all encaryotic and procaryotic thioredoxins and in S. thioredoxin. The thioredoxin and thioredoxin reductase genes in S. clavuligerus are in a cluster separated by 33 nucleotides, in contrast to the trxA and trxB genes of E. coli which are spread widely.