Activities | Families | Sequences | Fold types | References | Help
B6db references: 31342153

type Journal Article
authors Hasegawa D, Kito K, Maeda T, Rai V, Cha-Um S, Tanaka Y, Fukaya M, Takabe T
title Functional characterization of aminotransferase involved in serine and aspartate metabolism in a halotolerant cyanobacterium, Aphanothece halophytica
journal Protoplasma
sel selected
ui 31342153
year (2019)
volume 256
number 6
pages 1727-1736
keywords Aspartate aminotransferase; Betaine; LL-diaminopimelate aminotransferase; Peptidoglycan; Phosphoserine aminotransferase; Salt stress
abstract Aminotransferases catalyze the reversible pyridoxal phosphate-dependent transfer of amino groups from amino acids to oxo acids and play important roles for the balance between carbon and nitrogen metabolism. In this report, four aminotransferases (Ap1-Ap4) from a halotolerant cyanobacterium Aphanothece halophytica were examined. The results revealed that Ap1 and Ap2 exhibited the aspartate:2-oxoglutarate aminotransferase (AspAT) activity whereas Ap2 catalyzed further aminotransferase activities with alanine (AlaAT) and LL-diaminopimelate (an intermediate for the synthesis of Lys/peptidoglycan) as amino donors. Ap4 exhibited bifunctional aminotransferase with phosphoserine (PSAT) and glycine (GGAT) as amino donors. No activity was observed for Ap3. We identified third gene encoding phosphoserine phosphatase (PSP) in phosphorylate serine biosynthetic pathway. The levels of mRNA for Ap2 and ApMurE encoding UDP-N-acetylmuramoyl-L-alanyl-D-glutamate-2,6-diaminopimelate ligase were increased after salt stress. These results suggest the link among photorespiratory metabolite (serine, glycine, glyoxylate), phosphorylate serine biosynthetic pathway and aspartate metabolism via aminotransferases for the synthesis of peptidoglycan and betaine under salt stress conditions.
last changed 2020/02/20 10:47

B6db references