Characterization of DsrK and DsrO from Allochromatium vinosum and other Proteobacteria Using the Amino Acid Sequences
Sulfur metabolism is one of the oldest known redox geochemical cycles in our environment. One of the operons involved in this process is called dsr operon. The operon is involved in the balancing and utilization of environmental sulphur compounds. One of the central players of this operon is DsrMKJOP complex. DsrO is a periplasmic protein and binds FeS clusters which is mainly responsible for electron transfer to DsrP. DsrP could be involved in electron transfer from DsrP to DsrM. DsrM would then donate electrons to DsrK, the catalytic subunit of this complex. In the present study we tried to analyze the probable molecular details of DsrO and DsrK proteins from a diverse set of microbial species using only their sequence information. There are certain mutations present in the conserved domain of the protein. Those mutations confer some additional functionality to the protein. Sequences of the DsrO and DsrK proteins from different proteobacterial species have been analyzed to study the effects of mutations in the sequences and a phylogenetic relationship between the organisms has been drawn. We analyzed the secondary structural patterns of the DsrK and DsrO proteins also. There are no previous reports that deal with the bioinformatic analysis of the DsrO and DsrK protein. This is so far the first report of its kind. Our study would therefore pave the pathway to future genetic and mutational studies using DsrK and DsrO proteins that would lead to illumination of the biochemical mechanism of sulphur metabolism.
Semanti Ghosh, and Angshuman Bagchi