TY - JOUR
T1 - An unusual metal-bound 4-fluorothreonine transaldolase from Streptomyces sp. MA37 catalyses promiscuous transaldol reactions
AU - Wu, Linrui
AU - Tong, Ming Him
AU - Raab, Andrea
AU - Fang, Qing
AU - Wang, Shan
AU - Kyeremeh, Kwaku
AU - Yu, Yi
AU - Deng, Hai
N1 - Publisher Copyright:
© 2020, The Author(s).
PY - 2020/5/1
Y1 - 2020/5/1
N2 - β-Hydroxy-α-amino acids (βH-AAs) are key components of many bioactive molecules as well as exist as specialised metabolites. Among these βH-AAs, 4-fluorothreonine (4-FT) is the only naturally occurring fluorinated AA discovered thus far. Here we report overexpression and biochemical characterisation of 4-fluorothreonine transaldolase from Streptomyces sp. MA37 (FTaseMA), a homologue of FTase previously identified in the biosynthesis of 4-FT in S. cattleya. FTaseMA displays considerable substrate plasticity to generate 4-FT as well as other β-hydroxy-α-amino acids with various functionalities at C4 position, giving the prospect of new chemo-enzymatic applications. The enzyme has a hybrid of two catalytic domains, serine hydroxymethyltransferase (S) and aldolase (A). Site-directed mutagenesis allowed the identification of the key residues of FTases, suggesting that the active site of A domain has a historical reminiscent feature in metal-dependent aldolases. Elemental analysis demonstrated that FTaseMA is indeed a Zn2+-dependent enzyme, the first example of pyridoxal phosphate (PLP) enzyme family fused with a metal-binding domain carrying out a distinct catalytic role. Finally, FTaseMA showed divergent evolutionary origin with other PLP dependent enzymes.
AB - β-Hydroxy-α-amino acids (βH-AAs) are key components of many bioactive molecules as well as exist as specialised metabolites. Among these βH-AAs, 4-fluorothreonine (4-FT) is the only naturally occurring fluorinated AA discovered thus far. Here we report overexpression and biochemical characterisation of 4-fluorothreonine transaldolase from Streptomyces sp. MA37 (FTaseMA), a homologue of FTase previously identified in the biosynthesis of 4-FT in S. cattleya. FTaseMA displays considerable substrate plasticity to generate 4-FT as well as other β-hydroxy-α-amino acids with various functionalities at C4 position, giving the prospect of new chemo-enzymatic applications. The enzyme has a hybrid of two catalytic domains, serine hydroxymethyltransferase (S) and aldolase (A). Site-directed mutagenesis allowed the identification of the key residues of FTases, suggesting that the active site of A domain has a historical reminiscent feature in metal-dependent aldolases. Elemental analysis demonstrated that FTaseMA is indeed a Zn2+-dependent enzyme, the first example of pyridoxal phosphate (PLP) enzyme family fused with a metal-binding domain carrying out a distinct catalytic role. Finally, FTaseMA showed divergent evolutionary origin with other PLP dependent enzymes.
KW - 4-fluorothreonine
KW - 4-fluorothreonine transaldolase
KW - Streptomyces sp. MA37
KW - Transaldolation
KW - β-Hydroxy-α-amino acids
UR - http://www.scopus.com/inward/record.url?scp=85081635980&partnerID=8YFLogxK
U2 - 10.1007/s00253-020-10497-z
DO - 10.1007/s00253-020-10497-z
M3 - Article
C2 - 32140842
AN - SCOPUS:85081635980
SN - 0175-7598
VL - 104
SP - 3885
EP - 3896
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
IS - 9
ER -