Now that complete genome sequences are available for a variety of organisms, the 
elucidation of potential gene products function is a central goal in the 
post-genome era. Domain fusion analysis has been proposed recently to infer the 
functional association of the component proteins. Here, we took a new approach 
to the analysis of the structural features of the proteins involved in fusion 
events. An exhaustive survey of fusion events within 30 completely sequenced 
genomes and subsequent structure annotations to the component proteins at a SCOP 
superfamily level with hidden Markov models was carried out. A domain fusion map 
was then constructed. The results revealed that proteins with the class 
alpha/beta fold are frequently involved in fusion events, around 86% of the 
total 676 assigned single-domain fusion pairs including at least one component 
protein belonging to the alpha/beta fold class. Moreover, the domain fusion map 
in our work may offer an attractive framework for designing chimeric enzymes 
following Nature's lead, and may give useful hints for exploring the 
evolutionary history of proteins. (c) 2002 Elsevier Science Ltd.