Figure 1.

The growth over time of the number of proteins known versus the growth in the number of unique domains. The left axis and red line are the cumulative sum of proteins in the NCBI Entrez Protein Database discovered in that year and in all previous years. The right axis and blue line are the total number of unique domains from the Conserved Domain Database that can be found in the cumulative set of proteins for each year, found by running RPS-BLAST on the set of proteins. Note that the zero slope in recent years may be caused by the need to accumulate multiple sequences to create a domain profile. However, this does not explain the inflection point in the curve beginning in 1990.