WEST LAFAYETTE, Ind. – The crystallized form of a molecular machine that can cut and paste genetic material is revealing possible new paths for treating diseases such as some forms of cancer and opportunistic infections that plague HIV patients. Purdue University researchers froze one of these molecular machines, which are chemical complexes known as a Group I intron, at mid-point in its work cycle. When frozen, crystallized introns reveal their structure and the sites at which they bind with various molecules to cause biochemical reactions. Scientists can use this knowledge to manipulate the intron to splice out malfunctioning genes, said...