To access the data, click or select the words “Appendix 4.” Appendix 6 to view the entire tilt series and the segmented reconstructed volume. (A) Still image from a single slice through a tomographic reconstruction. (B) Manually-segmented reconstructed volume of the collagen VI molecules and proteoglycans, depicted in (A). The dark transverse bands (N- and C- globular domains) are shown in blue, the collagenous triple-helices in pink, and proteoglycans in yellow. Proteoglycans vary in size and interact with the terminal globular domains and/or the triple helices (purple arrowheads). White arrowheads point to interacting collagenous domains. Lateral associations of adjacent aggregates are indicated by the green arrowheads. A red arrowhead indicates a double band, characteristic of collagen VI. Scale bar=100 nm.