GIRTGIQ – sequence in C1q to which is attributed the “kink” in the collagen like domain of C1q (Pfliegers et al) . They write “The two following interruptions in the Gly-Y-Z triplet repeats are involved in the kink of the collagen-like region,i.e.the insertion of a threonine at position 39 in the A chain and the replacement of a glycine by an alanine at position 36 in the C chain”. Also they suggest three lysines (58,59 and 61in A,B and C chains) along the collagen-like domain are likely where interaction sites with C1r and C1s proteases becoming the C1 complex. Their pictures are wonderful.