TY - JOUR
T1 - Purification and characterization of a novel nitrile hydratase from Rhodococcus sp. RHA1
AU - Okamoto, Sachi
AU - Eltis, Lindsay D.
PY - 2007/8
Y1 - 2007/8
N2 - The microbial degradation of nitriles is of interest for bioremediation and green chemistry. We demonstrated that the soil bacterium Rhodococcus sp. RHA1 utilizes a range of nitriles, including acetonitrile, as growth substrates. Proteomic analysis identified 13 proteins that were more abundant in acetonitrile-grown cells, including an aliphatic amidase and a protein with no known homologue. Purification of a nitrile hydratase (NHase) from acetonitrile-grown cells identified the unknown protein as the β subunit of a two-subunit NHase. Sequence analysis revealed that the genes encoding the amidase (anhC) and the NHase (anhAB) occur in a 12.8 kbp cluster located on plasmid pRHL2. The anh gene cluster also encodes an acetyl-CoA hydrolase, transcriptional regulators, a putative cobalt transporter and a protein of unknown function. Striking features of the NHase include the amino acid sequence identity (32%) and large size (63 and 56 kDa) of the α and β subunits, as well as the enzyme's metal ion content (one cobalt, two copper and one zinc). The enzyme possessed similar specificities for acetonitrile and propionitrile (kcat/Km∼7 mM-1 s -1) followed by acrylonitrile and butyronitrile. We propose that this acetonitrile hydratase (ANHase) represents the first member of a previously unknown class of NHases.
AB - The microbial degradation of nitriles is of interest for bioremediation and green chemistry. We demonstrated that the soil bacterium Rhodococcus sp. RHA1 utilizes a range of nitriles, including acetonitrile, as growth substrates. Proteomic analysis identified 13 proteins that were more abundant in acetonitrile-grown cells, including an aliphatic amidase and a protein with no known homologue. Purification of a nitrile hydratase (NHase) from acetonitrile-grown cells identified the unknown protein as the β subunit of a two-subunit NHase. Sequence analysis revealed that the genes encoding the amidase (anhC) and the NHase (anhAB) occur in a 12.8 kbp cluster located on plasmid pRHL2. The anh gene cluster also encodes an acetyl-CoA hydrolase, transcriptional regulators, a putative cobalt transporter and a protein of unknown function. Striking features of the NHase include the amino acid sequence identity (32%) and large size (63 and 56 kDa) of the α and β subunits, as well as the enzyme's metal ion content (one cobalt, two copper and one zinc). The enzyme possessed similar specificities for acetonitrile and propionitrile (kcat/Km∼7 mM-1 s -1) followed by acrylonitrile and butyronitrile. We propose that this acetonitrile hydratase (ANHase) represents the first member of a previously unknown class of NHases.
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U2 - 10.1111/j.1365-2958.2007.05834.x
DO - 10.1111/j.1365-2958.2007.05834.x
M3 - Article
C2 - 17635193
AN - SCOPUS:34447569328
VL - 65
SP - 828
EP - 838
JO - Molecular Microbiology
JF - Molecular Microbiology
SN - 0950-382X
IS - 3
ER -