... Eggertsson1 and Magnu´s M. Kristja´nsson21Institute of Biology, University of Iceland; and 2Department of Biochemistry, Science Institute, University of Iceland,Reykjavik, IcelandThe gene ... elements based on knowncrystal structures of PRK are indicated by h(helix) and s (strand) and calcium bindingligands (P175, V177 and D200 at theCa1 site and T16 and D260 at the Ca2 site,according ... domain of VPR additionally contains Cys277 and Cys281, and Cys351 and Cys362 in the C-terminal domain, that suppo-sedly also form disulfide bonds as the enzyme has not beenfound to contain any free...