Two postdoctoral positions are available immediately in the lab
of*/Carrie Wilmot/*(University of Minnesota, Minneapolis, USA) to
structurally characterize the catalytic mechanismsof two heme enzymes,
chlorite dismutase and MauG.
*/Chlorite dismutase/***(Cld) is a /b/-type mono-heme enzyme capable of
rapidly and selectively decomposing chlorite to Cl¯ and O_2 . The
ability of Cld to promote O_2 formation from chlorite (ClO_2 ¯)_is
unusual, making Cld the only known enzymatic system outside of
photosystem II that has evolved to efficiently catalyze O-O bond
formation. We have recently solved the X-ray crystal structure of
/Dechloromonas aromatica /Cld (Goblirsch et al (2010) /J. Biol. Inorg.
Chem./ 15: 879-88). Cld was first isolated and characterized from
perchlorate respiring organisms, where the enzyme is involved in the
breakdown of perchlorate, a serious fresh water pollutant that leads to
thyroid dysfunction. It is now clear that gene sequences annotated as
/clds/ are extremely widespread in ~500 highly taxonomically diverse
organisms, the overwhelming majority of which do not respire
perchlorate. In addition to studying the mechanism of Cld catalyzed
chlorite dismutation, we are interested in the function of these
uncharacterized homologs.
The project will involve X-ray crystallography, single crystal
spectroscopy (UV-visible, X-ray absorption) and freeze trapping of
catalytic intermediates in the crystal for structural studies.
*/MauG/*is a di-heme enzyme responsible for the posttranslational
modification of two tryptophan residues to form the tryptophan
tryptophylquinone cofactor (TTQ) of methylamine dehydrogenase (MADH).
MauG converts preMADH, the precursor protein containing
monohydroxylated-?Trp57, to fully functional MADH by catalyzing the
insertion of a second oxygen atom into the indole ring and covalently
linking ?Trp57 to ?Trp108. We have recently solved the X-ray crystal
structure of MauG complexed with preMADH (Jensen et al. (2010) /Science
/327: 1392-4). The /c/-type heme irons and the nascent TTQ site are
separated by long distances over which electron transfer must occur to
achieve catalysis. In addition one of the hemes has an atypical His-Tyr
axial ligation. The crystalline protein complex is catalytically
competent, as on addition of hydrogen peroxide MauG-dependent TTQ
synthesis occurs.
The project will involve X-ray crystallography, mass spectrometry,
single crystal spectroscopy (UV-visible, Raman, X-ray absorption) and
freeze trapping catalytic intermediates in the crystal.
The positions are available immediately, with a highly competitive
salary commensurate with experience. Applicants must have a recent Ph.D.
in biochemistry, chemistry, molecular biology or a closely related
field.*/Applicants should have demonstrated expertise in macromolecular
crystallography/*.
Candidates should submit a cover letter that includes a brief statement
of previous research experience and interests, along with a detailed CV
and the names of 3 references. Review of applications will start
immediately and continue until the positions are filled.
For additional information or to make an application contact:
Dr. Carrie Wilmot,
Associate Professor and Director of the Kahlert Structural Biology
Laboratory,
University of Minnesota,
Department of Biochemistry, Molecular Biology & Biophysics,
6-155 Jackson Hall, 321 Church St SE,
Minneapolis, MN 55455-0215, USA.
E-mail: [email protected]
Tel: +1-612-624-2406
WWW: http://www.cbs.umn.edu/BMBB/html/Faculty/Wilmot.C.M.html
<http://www.cbs.umn.edu/BMBB/html/Faculty/Wilmot.C.M.html>
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