Domain duplication

Williams, N.A., Holland, P.W.H. 1998. Gene and domain duplication in the chordate Otx family insights from amphioxus Otx. Mol. Biol. Evol. 15, 600-607. 

Centrins are calmodulin-like proteins that have an important function in the organization and duplication of microtubules. Like CaM, centrin is also comprized of two structurally independent globular domains connected by a flexible tether, and each domain is... 

In a contribution dealing with two related compound classes, space could be saved by treating them together in domains where they display close similarities. However, the only spheres where this applies to sulphones and sulphoxides are elemental sulphur determination and chromatography. The former is too unspecific to be considered for inclusion in this chapter. Chromatographic behaviour is determined by the whole molecule, but the widespread use of chromatographic methods does justify its treatment. At the risk of a very little duplication it has been deemed more suitable to provide separate accounts of the two compound classes. 

The three-dimensional structure of HRP C is largely a-helical, although there is also a small region of (3-sheet. There are two domains, the distal and proximal, between which the heme group is located. These domains probably originated as a result of gene duplication, a proposal supported by their common calcium binding sites and other structural elements (Veitch 2004). 

The evolutionary hypothesis is that the ancestral molecule of apo(a) was a plasminogen-type protein, having five kringles, that emerged by a duplication event from a protein with one kringle and one serine protease domain about 300 million years ago (12). 

It can be difficult to decide where exactly to cut a protein so as to cleanly excise each domain. It is not always certain that the duplications that gave rise to the domains happened by the simple duplication of entire domains. Fractions of domains or units containing the C-terminal half of one domain and the N-terminal half of an adjoining domain could, in principle, be duplicated. These pathological cases can be teased out only by close inspection and the careful use of profile analysis and dot-matrix plots (e.g., Gibson et al, 1993). 

The EU funded Interpro project is a collaboration between many of the domain family databases and the SWISS-PROT sequence database. The Interpro collaboration aims to have a centralized annotation resources to reduce the amount of duplication between the database re-... 

Teichmann, S. A., Park, J., and Chothia, C. (1998). Structural assignments to the Mycoplasma genitalium proteins show extensive gene duplications and domain rearrangements. Proc. Natl. Acad. Sd. U.S.A. 95, 14658—14663. 

For proteins with more than two domains, each potential duplication is listed separately e.g., a minimum of two duplications would be necessary to produce either a three-domain or a four-domain structure. Members of the pairs in the left-hand column both fall within the same structural subcategory and have fairly similar topologies such pairs are perhaps the result of internal gene duplications. Members of pairs in the right-hand column almost all fall into different major categories of tertiary structure (e.g., one all-helical and one antiparallel jS) presumably they could not have been produced by internal gene duplication. 

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