HR: 1340h
AN: B33A-0859    [Abstracts]
TI: Localisation and Functional Analysis of a Manganese Oxidase Protein From the Marine Alpha-Proteobacterium Aurantimonas manganoxydans (sp. SI85-9A1)
AU: * Anderson, C R
EM: andersoc@ebs.ogi.edu
AF: Environmental and Biomolecular Systems Department OHSU School of Science and Engineering, 20000 NW Walker Road, Beaverton, OR 97006, United States
AU: Davis, R
EM: davisr@ebs.ogi.edu
AF: Environmental and Biomolecular Systems Department OHSU School of Science and Engineering, 20000 NW Walker Road, Beaverton, OR 97006, United States
AU: Tebo, B
EM: tebo@ebs.ogi.edu
AF: Environmental and Biomolecular Systems Department OHSU School of Science and Engineering, 20000 NW Walker Road, Beaverton, OR 97006, United States
AB: The marine α-proteobacterium SI85-9A1 was isolated in 1985 from the oxic-anoxic transition zone in Sannich Inlet, Vancouver Island, Canada. This organism was originally isolated due to its ability to oxidise manganese from Mn(II) to Mn(IV) oxides. It later proved to have a functional Type I RuBisCO suggesting it can potentially grow autotrophically with Mn(II) acting as the electron donor. Until now the mechanism of Mn(II) oxidation has remained enigmatic although clues from the genome and preliminary experiments suggested SI85-9A1 possessed a manganese oxidase similar to the Mox oxidase produced by Pedomicrobium sp. ACM 3067. Whole cell fractionation techniques were used to localise this protein to the outer membrane where it is loosely bound and can be washed off. Manganese oxidation activity in non-pure crude extracts was analysed using an LBB colorimetric assay and monitoring Mn(III)-pyrophosphate complex formation at 258 nm in a Mn(III) capture assay. Both these assays not only confirmed function but suggested that this protein is extremely active with a manganese oxidation rate approaching 8.9 μM min^-1 mg^-1. Partial FPLC purification confirmed that this protein was approximately 50 KD in size and may be part of a larger holoenzyme.
DE: 0448 Geomicrobiology
DE: 0461 Metals
DE: 4851 Oxidation/reduction reactions (0471)
DE: 4875 Trace elements (0489)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting