A protein complex consisting of three collagen chains assembled into a left-handed triple helix. These trimers typically assemble into higher order structures. [ http://www.ncbi.nlm.nih.gov/pubmed/19693541 GOC:mah GOC:dos https://www.worldcat.org/search?q=bn%3A0721639976 http://www.ncbi.nlm.nih.gov/pubmed/21421911 ]