L-threonine　aldolase　(LTA)　is　a　PLP-dependent　enzyme　that　can　reversibly　catalyze　aldol　reaction　of　glycine　and　acetaldehyde　to　produce　beta-hydroxy-alpha-amino　acids.　In　the　present　work,　a　putative　Ita　gene　from　Actinocorallia　herbida　(AhLTA)　was　mined　and　over-expressed　in　Escherichia　coli　BL21　(DE3).　The　substrate　spectrum　assay　indicated　that　AhLTA　only　used　glycine　as　donor　substrate　and　tolerated　a　wild　range　of　aromatic　aldehydes　as　acceptor　substrates.　It　was　found　that　the　type　and　position　of　substituents　in　the　aromatic　aldehydes　exerted　a　significant　impact　on　the　activity　and　stereoselectivity　at　beta-carbon　of　AhLTA.　Among　those　substrates,　AhLTA　could　catalyze　glycine　and　4-methylsulphonyl　benzaldehyde　(14a)　to　produce　L-threo-4-methylsulfonylphenylserine　((2S,3R)-14b)　with　high　conversion　(94.4%)　and　moderate　stereoselectivity　(19%　de).　By　conditional　optimization,　the　de　value　of　(2S,　3R)-14b　was　improved　to　61%　and　the　conversion　was　75%.　Taken　together,　our　study　suggested　that　AhLTA　might　be　a　promising　catalyst　for　producing　chiral　beta-hydroxy-alpha-amino　acids.　(C)　2020　Elsevier　Ltd.　All　rights　reserved.