My research interests focus on the structure-function study of enzymes in the vitamin K cycle. This cycle participates in post-translational modification of proteins involved in a broad range of biological functions including blood coagulation, bone homeostasis, signal transduction, and other cell control systems. γ-Glutamyl carboxylase (GGCX) and vitamin K epoxide reductase (VKOR) are the two enzymes currently known in this cycle. Both enzymes are integral polytopic proteins localized in the endoplasmic reticulum. The identity of vitamin K reductase (VKR), one of the key enzymes in the vitamin K cycle, is still unknown. Through biochemical, molecular and cellular approaches, I seek to investigate how these enzymes function in their native milieu and how natural mutations in these enzymes lead to distinct genetic disorders. My present study focuses on the identification of VKR using the novel genome editing tool CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated protein) system.