Subsystem: Pyridoxin (Vitamin B6) Biosynthesis

This subsystem's description is:

Vitamin B6 in its active form pyridoxal phosphate (PLP) is an essential coenzyme of many diverse enzymes. PLP has multiple roles as a versatile cofactor of enzymes that are mainly involved in the metabolism of amino acid compounds. Moreover, VB6 appears to play an important role against photosensitization in fungi. Most unicellular organisms and plants biosynthesize PLP by themselves.

Three metabolic pathways for pyridoxal 5'-phosphate are known (ref. 1, 2):
-the de novo pathway,
-the salvage pathway,
-and the Alternate (yeast/fungal type) pathway.

Most unicellular organisms and plants biosynthesize VB6 using one or two of these three biosynthetic pathways. However, animals such as insects and mammals do not possess any of the pathways and, thus, need to intake VB6 in their diet to survive.

======VARIANT CODES:================

1.0 - De novo pathway,
1.x - some genes are missed from the De novo pathway;
2.0 - de novo pathway and salvage pathway
2.x - de novo pathway with some genes missed and salvage pathway;
3.0 - Salvage pathway;
4.0 - the Alternate (yeast/fungal type) pathway;
5.0 - de novo pathway + salvage pathway + Alternate pathway;
5.x - de novo pathway with some genes missed, salvage pathway and Alternate pathway ( as in Deinococcus radiodurans R1);
6.0 - some genes of de novo pathway and Alternate pathway ( as in Listeria) ternate pathway ( as in Listeria)

For more information, please check out the description and the additional notes tabs, below

Literature ReferencesTwo independent routes of de novo vitamin B6 biosynthesis: not that different after all. Fitzpatrick TB The Biochemical journal 2007 Oct 117822383
serC is involved in vitamin B6 biosynthesis in Escherichia coli but not in Bacillus subtilis. Sakai A Journal of bioscience and bioengineering 200216233211
Involvement of the gapA- and epd (gapB)-encoded dehydrogenases in pyridoxal 5'-phosphate coenzyme biosynthesis in Escherichia coli K-12. Yang Y Journal of bacteriology 1998 Aug9696782
DiagramFunctional RolesSubsystem SpreadsheetDescriptionAdditional NotesScenarios 

Showing colors for genome: Sulfolobus acidocaldarius DSM 639 ( 330779.3 ), variant code 4.0

This diagram is not scaled.