Solution structure of the fifth repeat of factor H: a second example of the complement control protein module

A technique using combined two-dimensional NMR and simulated annealing process was used to demonstrate the three-dimensional structure of the fifth repeat of human factor H (H5). H5 contained 17 amino acids that were homologous and similarly positioned to that of the 16th repeat of human factor H (H16). H5 and H16 shared major similarities in their secondary structures and their tertiary structures have overall resemblance with each other. The significant differences in their structures were the deletion in the primary strand of H5 and an insertion in its loop that shorten its length.