A nano switch mechanism for the redox-responsive sulfotransferase.

Cellular redox signaling is important in diverse physiological and pathological processes. The activity of rat phenol sulfotransferase (rSULT1A1), which is important for the metabolism of hormone and drug, is subjected to redox regulation. Two cysteines, Cys232 and Cys66, nanometer away from each other and from the enzyme active site were proposed to form disulfide bond to regulate the activity of rSULT1A1.

Dynamics and evolution of the inverted repeat-large single copy junctions in the chloroplast genomes of monocots.

Background: Various expansions or contractions of inverted repeats (IRs) in chloroplast genomes led to fluxes in the IR-LSC (large single copy) junctions. Previous studies revealed that some monocot IRs contain a trnH-rps19 gene cluster, and it has been speculated that this may be an evidence of a duplication event prior to the divergence of monocot lineages. Therefore, we compared the organizations of genes flanking two IR-LSC junctions in 123 angiosperm representatives to uncover the evolutionary dynamics of IR-LSC junctions in basal angiosperms and monocots.

Mechanism of posttranslational regulation of phenol sulfotransferase: expression of two enzyme forms through redox modification and nucleotide binding.

Sulfotransferase catalyzes sulfuryl group transfer between a nucleotide and a variety of nucleophiles that may be sugar, protein, xenobiotics, and other small molecules. Nucleotides may serve as cosubstrate, cofactor, inhibitor, or regulator in an enzyme catalyzed sulfuryl group transfer reaction. We are trying to understand how nucleotide regulates the activity of phenol sulfotransferase (PST) through the expression of two enzyme forms.