Other interests of the Structural Biology Section include to understand enzymatic mechanisms of certain novel enzymatic reactions, particularly reactions utilizing rare transition metals. Trace of these metallic elements, such as molybdenum and selenium, are essential to normal cellular functions. Their level in cell is delicately balanced in that too much will lead to cytotoxicity and too little will cause several types of deficient syndromes. For example, selenium deficiency can result anemia, abnormality in thyroid hormone metabolism and congestive cardiomyopathy and molybdenum deficiency will lead to abnormally small brain, and death of infants within a few days of birth. Formate dehydrogenase H (FDH) from E. coli is an example that contains multiple redox centers, which include a molybdopterin cofactor, an iron-sulfur cluster and a natural selenocysteine residue at its active site and catalyzes the two-electron oxidation of formate to carbon dioxide.