Research Interests   Microbial Biochemistry; Redox Proteins; N-Oxidation; Microbial Detoxification

We study the structure, catalysis and evolution of the metallo-enzymes which oxidize hydrox to nitrite in the chemolithoautotrophic bacterium, Nitrosomonas. The remarkable hydroxylamine oxidoreductase contains 8 covalently bound c-hemes the catalytic heme also has a covalently crosslink to a tyrosine. One line of an evolutionary family of multiheme cytochromes derived from a pentaheme nitrite reductase includes an octaheme nitrite reductase and then the octaheme hydroxylamine oxidoreductases. A second line leads to leads to an octaheme tetrathinate reductase. A new family of beta-sheet c-cytochromes includes cytochrome P460, with a lys-heme covalent crosslink and the non-cross-linked cytoshrome c'-beta.

Hooper, A.B., Arciero, D.M., Bergmann, D., and Hendrich, M.P. (2005) The Oxidation of Ammonia as an Energy Source in Bacteria in Respiration in Davide Zannoni, Ed. Respiration in Archaea and Bacteria: Diversity of Procaryotic Respiratory Systems pp 121 – 147. Vol 16 of Advances in Photosynthesis and Respiration, Govindjee, Ed.   Springer,  Dordrecht, the Netherlands. 3297-13300.

Bergmann, D.B., Hooper, A.B. and Klotz, M., (2005) Structure and Sequence Conservation of hao Cluster Genes of Autotrophic Ammonia-Oxidizing Bacteria: Evidence for their Evolutionary History. Appl. Envt. Microbiol. 71: 5371 – 5382.

Elliot, S.J., Bradley, A. , Arciero, D.M. and Hooper, A.B. (2007) Protonation and Inhibition of Nitrosomonas europaea cytochrome c peroxidase observed with protein film voltammetry. J. Inorganic Biochemistry 101; 173 - 178.

Pulcu, G.S., Elmore, B.L., Arciero, D.M. Hooper, A.B. and Elliot, S.J. (2007) Direct electrochemistry of tetraheme cytochrome c554 from Nitrosomonas europaea: redox cooperativity and conformational gating. JACS129: 1838-9.

Elmore, B , Bergmann, D.B.,  Klotz, M., and Hooper, A.B.  (2007) Cytochromes-P460 and -c’-beta; a New Family of High-spin cytochromes c.FEBS Lett 581:911-6.

Pearson, A.R., Elmore, B.O., Yang, C., Ferrara, J.D., Hooper, A.B. & Wilmot, C.M. (2007) The crystal structure of cytochrome P460 of Nitrosomonas europea reveals a novel cytochrome fold and heme-protein cross-link. Biochemistry 46, 8340-8349.

Kim, H. J., ,Zatsman, A. ,Upadhyay, A. K.,  Whittaker, M.W., Bergmann, D.J.,  Hendrich, M.P. and Hooper, A.B. (2008)  Membrane Tetraheme Cytochrome cm552 of the Ammonia-Oxidizing Nitrosomonas europaea; a Ubiquinone Reductase.  Bioch.47, 6539-6551.