ABSTRACT
Analyses of human genome yield an estimate of about 20,000 genes [Venter et al. 2001, Lander et al. 2001, and subsequent estimates] in
Homo sapiens
, which is only about 40 times greater than the smallest sequenced genome,
Mycoplasma genitalium
, encoding ~470 genes. In higher organisms the number of proteins, however, may be an order of magnitude more than the number of genes due to alternative splicing, posttranslational modification and processing, etc. When this multiplicity is taken into account, the protein universe is even more vast and diverse.
