Figure 2.

(a) Average of 3,000 top 8-fold rings of a set of 13,646 rings from a single hDmc1 preparation. A symmetrized version of this average is shown in b. In one preparation of hDmc1 ≈10% of the protein existed as a large proteolytic fragment. From this preparation 15,948 rings were collected. (c) An average of 2,000 rings with the highest 8-fold symmetry is shown. (e) An average of 3,000 rings with the highest 7-fold symmetry is shown. (d and f) Eight-fold and 7-fold symmetrized versions, respectively, of these averages are shown. (g) An average of 605 double rings found on dsDNA substrates having ssDNA tails. The rings are spaced apart by ≈55 Å. The bipolar symmetry (each ring is facing in the opposite direction) of these structures can be seen by the similarity between the raw average (g) and a symmetrized version of this average (with mirror symmetry imposed) in h. (Scale bar in a is 100 Å.)