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- ***************************
- * Aspartokinase signature *
- ***************************
-
- Aspartokinase (EC 2.7.2.4) (AK) [1] catalyzes the first step in the conversion
- of L-aspartate to lysine, methionine and threonine.
-
- In Escherichia coli, there are three different isozymes which differ in their
- sensitivity to repression and inhibition by Lys, Met and Thr. AK1 (gene thrA)
- and AK2 (gene metL) are bifunctional enzymes which both consist of an N-
- terminal AK domain and a C-terminal homoserine dehydratase domain. AK1 is
- involved in threonine biosynthesis and AK2, in that of methionine. The third
- isozyme, AK3 (gene lysC), is monofunctional and involved in lysine synthesis.
- In yeast, there is a single isozyme of AK (gene HOM3).
-
- As a signature pattern for AK, we selected a conserved region located in the
- N-terminal extremity.
-
- -Consensus pattern: [LIVM]-x-K-[FY]-G-G-[ST]-S-[LIVM]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: June 1994 / Pattern and text revised.
-
- [ 1] Rafalski J.A., Falco S.C.
- J. Biol. Chem. 263:2146-2151(1988).
-