Servers with Information about Metabolic Functions

Groups of metabolic genes, graphics of pathways, unique characteristics, references, Internet sites.

ECOCYC: Encyclopedia of E. coli Genes and Metabolism
PUMA: Phylogeny of the Unicellular Organisms Metabolic Pathways Alignments; Note: this site has not been updated since early 1996. Try its replacement WIT listed below.
WIT: What Is There? Interactive Metabolic Construction on the Web
METALGEN