This ribbon-plot of the protein pentalenene synthase illustrates the unusual array of 11 alpha helices surrounding a central active site cavity approximately 15 angstroms deep and 9 angstroms wide. It is in this cavity that the actual cyclization reaction is believed to take place. The cavity is lined with an unusual proportion of phenylalanine, tyrosine and tryptophan amino acids, which appear to be ideally suited to bind and properly fold the substrate and to stabilize the highly reactive intermediates.
Courtesy of Professor David Cane
Return to news release 97-017.