Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Quantifying the mechanisms of domain gain in animal proteins. | Buljan et al. Genome Biology 2010 11 R74 http 2010 11 7 R74 Genome Biology RESEARCH Open Access Quantifying the mechanisms of domain gain in animal proteins Marija Buljan Adam Frankish Alex Bateman Abstract Background Protein domains are protein regions that are shared among different proteins and are frequently functionally and structurally independent from the rest of the protein. Novel domain combinations have a major role in evolutionary innovation. However the relative contributions of the different molecular mechanisms that underlie domain gains in animals are still unknown. By using animal gene phylogenies we were able to identify a set of high confidence domain gain events and by looking at their coding DNA investigate the causative mechanisms. Results Here we show that the major mechanism for gains of new domains in metazoan proteins is likely to be gene fusion through joining of exons from adjacent genes possibly mediated by non-allelic homologous recombination. Retroposition and insertion of exons into ancestral introns through intronic recombination are in contrast to previous expectations only minor contributors to domain gains and have accounted for less than 1 and 10 of high confidence domain gain events respectively. Additionally exonization of previously non-coding regions appears to be an important mechanism for addition of disordered segments to proteins. We observe that gene duplication has preceded domain gain in at least 80 of the gain events. Conclusions The interplay of gene duplication and domain gain demonstrates an important mechanism for fast neofunctionalization of genes. Background Protein domains are fundamental and largely independent units of protein structure and function that occur in a number of different combinations or domain architectures 1 . Most proteins have two or more domains 2 and interestingly more complex organisms have more complex domain architectures as well as a greater variety of domain .
