Complement component 1q: Difference between revisions

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===C1q chains A, B and C===

C1q is composed of 18 polypeptide chains: six A-chains, six B-chains, and six C-chains. Each chain contains a collagen-like region located near the N terminus and a C-terminal globular region. The A-, B-, and C-chains are arranged in the order A-C-B on chromosome 1.<ref name="entrez ciqa">{{cite web | title = Entrez Gene: C1QA complement component 1, q subcomponent, A chain| url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=712| accessdate = }}</ref>

== Domain ==

The C1q ___domain is a conserved [[protein ___domain]]. [[C1Q complex|C1q]] is a subunit of the C1 [[enzyme]] [[Protein complex|complex]] that activates the [[blood serum|serum]] [[complement system]]. C1q comprises 6 A, 6 B and 6 C [[polymer|chain]]s. These share the same topology, each possessing a small, globular [[N-terminal]] ___domain, a collagen-like Gly/Pro-rich central region, and a [[conserved sequence|conserved]] C-terminal region, the C1q ___domain.<ref name="pmid1706597">{{cite journal |vauthors=Sellar GC, Blake DJ, Reid KB | title = Characterization and organization of the genes encoding the A-, B- and C-chains of human complement subcomponent C1q. The complete derived amino acid sequence of human C1q | journal = Biochem. J. | volume = 274 | issue = 2| pages = 481–90 |date=March 1991 | pmid = 1706597 | pmc = 1150164 | doi = 10.1042/bj2740481| url = }}</ref> The C1q protein is produced in collagen-producing [[cell (biology)|cell]]s and shows [[sequence (biology)|sequence]] and structural similarity to [[collagen]]s VIII and X.<ref name="pmid2591537">{{cite journal |vauthors=Petry F, Reid KB, Loos M | title = Molecular cloning and characterization of the complementary DNA coding for the B-chain of murine Clq | journal = FEBS Lett. | volume = 258 | issue = 1 | pages = 89–93 |date=November 1989 | pmid = 2591537 | doi = 10.1016/0014-5793(89)81622-9| url = }}</ref><ref name="pmid2019595">{{cite journal |vauthors=Muragaki Y, Jacenko O, Apte S, Mattei MG, Ninomiya Y, Olsen BR | title = The alpha 2(VIII) collagen gene. A novel member of the short chain collagen family located on the human chromosome 1 | journal = J. Biol. Chem. | volume = 266 | issue = 12 | pages = 7721–7 |date=April 1991 | pmid = 2019595 }}</ref>

==Function==