   1.14.13.69 | evolution |
the enzyme belongs to the bacterial monooxygenases of the soluble di-iron MOs (SDIMOs) type, thereof the group 4 SDIMOs are four-component alkene monooxygenases from bacteria that grow on ethene and/or propene. Despite their sequence and substrate diversity, all the SDIMOs have similar biochemistries. Electrons are transferred from NADH to an oxidoreductase protein that contains flavin and iron-sulfur clusters, and thence to a catalytic hydroxylase (made of 2 to 3 proteins) that contains the binuclear iron active site. In the active site, one oxygen atom in O2 is reduced to water, while the other is activated to a high-energy state and attacks the substrate. The catalytic activity is acilitated by a small cofactor-independent coupling protein, and depending on the SDIMO family, other proteins, such as ferredoxins, may also be part of the MO-enzyme complex. Mycobacterium chubuense NBB4 is unique among hydrocarbon-oxidizing bacteria because it contains four different SDIMOs, in addition to a copper-containing MO, a P450, and an alkB homologue. Strain NBB4 has two group 4 SDIMOs (etnABCD and pmoABCD), an atypical group 3 SDIMO (smoXYB1C1Z), and a group 6 SDIMO (smoABCD). To date, there is experimental evidence that smoXYB1C1Z is a gaseous alkane/alkene MO and that etnABCD is an ethene MO. Comparison of SDIMO activities in whole cells of wild-type and recombinant bacteria, overview |
-, 763955 |
