The reconstruction of a helical structure from projections applied to a phage tail

A procedure has been described for 3 D-image reconstruction for helical biological structures, if more than one projection will be required to determine the contributing helical density-waves. The method was tested with a helical protein aggregate derived from a bacteriophage. The results showed the feasibility of the proposed scheme and yielded a low resolution picture (about 2.5 nm) of the protein structure.