FIGURE 5.

Generation of the starting linear rat MBL monomer model. A, crystal structure of the CRD and neck regions of MBL was joined to the collagen region to create an initial MBL monomer. A total of 5,000 conformationally randomized models were created (see under “Experimental Procedures”). Vector 1 was defined by the Gly-36 pair and the Gly-86 pair on chains B and C of the collagen region, and vector 2 was defined by the Val-93 pair and the Thr-131 pair on chains B and C in the CRD and neck region. Models with an inter-vector angle close to 180° defined the starting MBL model. B, starting MBL model was completed by addition of the three N-terminal cysteine-rich peptides in β-strand conformations at the N-terminal residues of the collagen region and the addition of four glycosylgalactosyl disaccharides to residues Lys-44, Lys-47, Lys-79, and Lys-82 in each of the three collagen polypeptide chains (gray). At the bottom, the rat MBL sequence is aligned with the four regions of MBL. The N-terminal cysteine residues involved in oligomerization and the interruption in the 19 Gly-Xaa-Yaa triplets are highlighted in gray.