Caulobacter crescentus CB15 Pathway: homoserine biosynthesis

Pathway diagram: homoserine biosynthesis

If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Locations of Mapped Genes:

Schematic showing all replicons, marked with selected genes

Superclasses: Biosynthesis Amino Acids Biosynthesis Other Amino Acid Biosynthesis

Pathway Summary from MetaCyc:
The homoserine biosynthesis pathway is a three-step pathway that converts L-aspartate into homoserine. Two of the three enzymes that catalyze the first step in this pathway are bifunctional, also serving to catalyze the final step in the pathway.

The final product of this pathway, homoserine, feeds into biosynthetic pathways for both threonine and methionine. Fittingly, this pathway is regulated by the outputs of both of those pathways. metL is repressed by abundant methionine. thrA is regulated by threonine- and isoleucine-dependent attenuation, and both the aspartate kinase and homoserine dehydrogenase activities of ThrA are inhibited by threonine. The middle enzymatic activity, aspartate semialdehyde dehydrogenase, is subject to some form of repression by both methionine and threonine.

Superpathways: superpathway of methionine biosynthesis (by sulfhydrylation) , isoleucine biosynthesis I , superpathway of methionine biosynthesis (transsulfuration) , homoserine and methionine biosynthesis , superpathway of S-adenosyl-L-methionine biosynthesis

Pathway Evidence Glyph:

Pathway evidence glyph

Key to pathway glyph edge colors: ?

  An enzyme catalyzing this reaction is present in this organism
  The reaction and any enzyme that catalyzes it (if one has been identified) is unique to this pathway

Created 14-Oct-1998 by Paley S , SRI International
Last-Curated ? 16-Aug-2007 by SRI International

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Page generated by SRI International Pathway Tools version 19.0 on Sat Aug 1, 2015, BIOCYC14B.