title: Structural insight for chain selection and stagger control in collagen.
abstract: Collagen plays a fundamental role in all known metazoans. In collagens three polypeptides form a unique triple-helical structure with a one-residue stagger to fit every third glycine residue in the inner core without disturbing the poly-proline type II helical conformation of each chain. There are homo- and hetero-trimeric types of collagen consisting of one, two or three distinct chains. Thus there must be mechanisms that control composition and stagger during collagen folding. Here, we uncover the structural basis for both chain selection and stagger formation of a collagen molecule. Three distinct chains (α1, α2 and α3) of the non-collagenous domain 2 (NC2) of type IX collagen are assembled to guide triple-helical sequences in the leading, middle and trailing positions. This unique domain opens the door for generating any fragment of collagen in its native composition and stagger.
authors.affiliation: Research Department, Shriners Hospital for Children, Portland, Oregon 97239, USA.|Department of Molecular Biology and Biochemistry, Oregon Health and Science University, Portland, Oregon 97239, USA.|Department of Nephrology and Hypertension, Vanderbilt University, Nashville, Tennessee 37235, USA.
authors.forename: Sergei P
authors.initials: SP
authors.lastname: Boudko
authors.affiliation: Research Department, Shriners Hospital for Children, Portland, Oregon 97239, USA.|Department of Molecular Biology and Biochemistry, Oregon Health and Science University, Portland, Oregon 97239, USA.
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Bächinger
mesh_terms: D000595:Amino Acid Sequence; D024081:Collagen Type IX / Q000737:chemistry* / Q000235:genetics*; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding; D000072417:Protein Domains; D017510:Protein Folding; D055503:Protein Multimerization; D017433:Protein Structure, Secondary
chemical_list: D024081:Collagen Type IX