Disease relevance of dsdC

• Southern blot hybridization revealed physical variability within the argW-dsdC region, even among 22 E. coli O18:K1:H7 isolates [1].

High impact information on dsdC

• The genome sequence of diarrheagenic E. coli isolates indicates that the csrRAKB genes for sucrose utilization are often substituted for dsdC and a portion of dsdX present at the argW-dsdCXA island of extraintestinal isolates [1].
• Also, the previous erroneous DNA sequence of the dsdC gene has been corrected [2].
• By combining genetic and biochemical studies, it is demonstrated that the regulatory region of the operon and the gene encoding the specific regulator of D-serine tolerance (dsdC) had been misplaced in previous work on the dsd system [2].
• The dsdXA genes are cotranscribed from a common promoter region present in the dsdX-dsdC intercistronic region [2].
• Operon fusions between the D-serine deaminase regulatory and structural genes and lacZ were constructed and used to examine the control of expression of the positive regulatory gene, dsdC [3].

Biological context of dsdC

• Merodiploid strains containing both dsdCp::Mu d (lac Apr) and dsdC+A+ produced only one-fourth as much beta-galactosidase as did the haploid dsdCp::Mu d (lac Apr) strains, indicating that the dsdC+ product repressed its own synthesis [3].

References