Ribbons representation of proteinase K structure generated using the graphics program "Ribbons" written by Mike Carson. Beta strands are collored green. Alpha helices are colored cyan. 310 helics are colored blue. The structure was built using ARP/wARP automated chain tracing program. The program requires only the structure factors and phases output by DM and the primary sequence of proteinase K. The structure pops out after about 1/2 hour of calculations.