A two-component monooxygenase for continuous denitration and dechlorination of chlorinated 4-nitrophenol in Ensifer sp. strain 22-1

Role of conserved arginine in HadA monooxygenase for 4‐nitrophenol and 4‐chlorophenol detoxification

“…CNP‐8, 10 Cn TcpA from C. nantongensis X1 T , 11 CnpA from Ensifer sp. strain 22‐1, 12 TftD from B. cepacia AC1100, 13 FpdA2 from Arthrobacter sp. IF1, 14 CphCI from A. chlorophenolicus A6, 15 NpsA1 from Rhodococcus sp .…”

“…Two‐component enzymes are of high interest for biocatalytic applications because the change of enzymatic properties via enzyme engineering is more convenient. The enzymes in the two‐component family along with their properties, substrate scope, and pathways are listed in Table 1 7–21 . Based on their initial product characterization, the reaction pathway can be divided into hydroquinone (HQ) and catechol (CC) pathways, which are designated in the hydroxylation step 3,4 .…”

“…The enzymes in the twocomponent family along with their properties, substrate scope, and pathways are listed in Table 1. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Based on their initial product characterization, the reaction pathway can be divided into hydroquinone (HQ) and catechol (CC) pathways, which are designated in the hydroxylation step. 3,4 As an example, the simple scheme for 4-nitrophenol (4NP) and 4-chlorophenol (4CP) mineralization is illustrated in Figure 1.…”

“…In the CC pathway, hydroxylation occurs at the ortho-position, generating nitrocatechol or chlorocatechol derivatives as a product. Based on pathway characterization in two-component NP/HP-degrading enzymes (Table 1), [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] most of the enzymes catalyze the reaction via the HQ pathway. Thus, the dominant group of enzymes might share some common structural features; however, there is no insightful information on the essential requirements for a particular function.…”

Genetic redundancy of 4‐hydroxybenzoate 3‐hydroxylase genes ensures the catabolic safety of Pigmentiphaga sp. H8 in 3‐bromo‐4‐hydroxybenzoate‐contaminated habitats

“…Complete phbh1 , phbh2 , and phbh3 genes were amplified by PCR and then cloned into pET29a(+). The resultant plasmids were transformed into E. coli BL21(DE3) for protein expression and purification through a Co‐Talon affinity resin column (GE Healthcare Life Sciences) using the method described previously (Ke et al, 2021). The purified target protein was detected using sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and then dialyzed in two litres of 20 mM Tris–HCl (pH 8.0) overnight to remove imidazole, Na 3 PO 4 , and NaCl.…”