Structure function relationship of Lactate dehydrogenase/ ϵ-crystallin from lenses of Indian spiny-tailed lizard (Uromastyx hardwickii)

Eye lens is a fascinating object to study protein evolution. lenses contain highly stable long-lived proteins with the least turnover. lens transparency is maintained by water soluble proteins classified into ubiquitous (α,β and γ crystallin) and taxon-specific lens crystallins. ubiquitous crystallins show great diversity among vertebrates and invertebrates due to selective pressure leading to adaptive conflict. taxon-specific lens crystallins,on the other hand,are products of gene sharing or gene duplication phenomenon where metabolic enzymes are recruited as crystallins in addition to their structural role. current investigation was designed to study the evolutionary changes and discriminating adaptations in lens proteins. for this purpose,indian spiny-tailed lizard uromastyx hardwickii was used as an evolutionary model. we report partial nucleotide sequence of ldh/ϵ- crystallin comprising of 628 bp corresponding to 209 amino acids from lenses of uromastyx hardwickii. to get more insight about the structure-function relationship,bioinformatics tools were used. homology between sequences of ϵ-crystallin and ldh and conservation of catalytic residues indicated that ϵ-crystallin is a result of recruitment through gene sharing phenomenon. copyright 2016 zoological society of pakistan.