|Gene:||TSB1||Accession Number: AT5G54810 (MetaCyc)|
Species: Arabidopsis thaliana col
The Arabidopsis tryptophan synthase, like all other characterized tryptophan synthases, is composed of an alpha and a beta subunit. The alpha subunit catalyzes the conversion of indole-3-glycerolphosphate to indole, and the beta subunit, encoded by this and several other genes in Arabidopsis, catalyzes the formation of tryptophan from indole and serine [Last91]. There are two separate classes of tryptophan synthase beta proteins. This enzyme, TSB1, belongs to "type 1." Meanwhile, TSBType2 from Arabidopsis is a functional "type 2" tryptophan synthase beta protein [Yin10].
At least one functional gene encoding the alpha subunit, TSA1, has been cloned by functional complementation of an Escherichia coli mutant[Radwanski95]. On the other hand, there are two closely related genes encoding the beta subunit, TSB1 and TSB2. TSB1 is the predominantly expressed, whose mRNA accounts for 90% of the TSB transcripts[Last91]. A TSB1 mutant was shown lost about 90% of tryptophan synthase beta subunit activity.
|Map Position: [22,281,820 -> 22,284,011]|
Relationship Links: InterPro:IN-FAMILY:IPR001926 , InterPro:IN-FAMILY:IPR006653 , InterPro:IN-FAMILY:IPR006654 , InterPro:IN-FAMILY:IPR023026 , Panther:IN-FAMILY:PTHR10314:SF3 , Pfam:IN-FAMILY:PF00291 , Prosite:IN-FAMILY:PS00168
|Cellular Component:||GO:0009536 - plastid [Last91]|
Enzymatic reaction of: tryptophan synthase
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
The reaction is favored in the direction shown.
In Pathways: tryptophan biosynthesis
Last91: Last RL, Bissinger PH, Mahoney DJ, Radwanski ER, Fink GR (1991). "Tryptophan mutants in Arabidopsis: the consequences of duplicated tryptophan synthase beta genes." Plant Cell 3(4);345-58. PMID: 1840915
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