Molecular analysis of the grd operon coding for genes of the glycine reductase and of the thioredoxin system from Clostridium sticklandii

Graentzdoerffer, A Pich, A Andreesen, JR

A. Graentzdoerffer et al., Molecular analysis of the grd operon coding for genes of the glycine reductase and of the thioredoxin system from Clostridium sticklandii, ARCH MICROB, 175(1), 2001, pp. 8-18

44

INGLESE

Article

Microbiology

ARCHIVES OF MICROBIOLOGY

0302-8933 → ACNP

175

1

2001

8 - 18

ISI

0302-8933(200101)175:1<8:MAOTGO>2.0.ZU;2-G

A probe based on the sequence of the gene encoding selenoprotein A of glyci ne reductase of Clostridium sticklandii was used to obtain clones of adjace nt DNA that encoded the other components of glycine reductase, proteins B a nd C, in addition to thioredoxin and thioredoxin reductase. The genes of th e thioredoxin system and the glycine reductase were shown to be transcribed together, confirming an operon structure. In addition, a gene (grdX) encod ing a 13.7-kDa protein of unknown function seemed to be associated with the reductase genes. Four potential promoters were identified by mapping the 5 '-end of the mRNAs. The sequence of promoter P1 was shown to be similar to the sigma (70) promoter consensus sequence. The other three promoters were similar to each other, but not to known promoter consensus sequences. The t ranscripts starting at each of the four promoters were terminated to about 80% at a predicted loop structure downstream of grdB; the remaining transcr ipts continued through this structure and covered the genes encoding both s ubunits of protein C and bmpA, a gene that was also expressed monocistronic ally.