This research project concerns the study of enzyme reaction mechanisms, protein structure-function relationships, protein-protein interactions, protein biosynthesis, and mechanisms of long range biological electron transfer. The results of these studies are helping us to understand mechanisms by which enzymes catalyze reactions, and the molecular details of biological energy transduction and respiration. The proposed studies focus on the tryptophan tryptophylquinone [TTQ] bearing enzyme, methylamine dehydrogenase [MADH], and the electron transfer complex it forms with the type I copper protein amicyanin, and cytochrome c-551i . The proteins in this project have been crystallized free and in complex, and protocols have been established for altering the proteins by site-directed mutagenesis and analyzing their physical properties and physiological functions. This allows us define specific structure-function relationships. Elucidation of factors which influence the specific protein-protein interactions that are required for efficient interprotein electron transfer is providing insight into the process of protein-protein recognition that is common to a wide range of biologic phenomena. Characterization of the catalytic reaction mechanisms of quinoproteins is allowing us to better understand how enzymes, in general, catalyze reactions. Definition of the mechanisms of long range intermolecular electron transfer will allow us to better understand the fundamental processes of respiration and intermediary metabolism at the molecular level. Description of the mechanism of biosynthesis of MADH and TTQ will be relevant to understanding the mechanisms of biosynthesis of complex redox proteins, as well as mechanisms of protein biosynthesis and posttranslational modification of proteins in general.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM041574-16
Application #
6603829
Study Section
Physical Biochemistry Study Section (PB)
Program Officer
Ikeda, Richard A
Project Start
1988-08-01
Project End
2005-07-31
Budget Start
2003-08-01
Budget End
2004-07-31
Support Year
16
Fiscal Year
2003
Total Cost
$299,000
Indirect Cost
Name
University of Mississippi Medical Center
Department
Biochemistry
Type
Schools of Medicine
DUNS #
928824473
City
Jackson
State
MS
Country
United States
Zip Code
39216
Roessler, Christian G; Agarwal, Rakhi; Allaire, Marc et al. (2016) Acoustic Injectors for Drop-On-Demand Serial Femtosecond Crystallography. Structure 24:631-640
Yukl, Erik T; Jensen, Lyndal M R; Davidson, Victor L et al. (2013) Structures of MauG in complex with quinol and quinone MADH. Acta Crystallogr Sect F Struct Biol Cryst Commun 69:738-43
Geng, Jiafeng; Dornevil, Kednerlin; Davidson, Victor L et al. (2013) Tryptophan-mediated charge-resonance stabilization in the bis-Fe(IV) redox state of MauG. Proc Natl Acad Sci U S A 110:9639-44
Davidson, Victor L; Wilmot, Carrie M (2013) Posttranslational biosynthesis of the protein-derived cofactor tryptophan tryptophylquinone. Annu Rev Biochem 82:531-50
Abu Tarboush, Nafez; Jensen, Lyndal M R; Wilmot, Carrie M et al. (2013) A Trp199Glu MauG variant reveals a role for Trp199 interactions with pre-methylamine dehydrogenase during tryptophan tryptophylquinone biosynthesis. FEBS Lett 587:1736-41
Yukl, Erik T; Liu, Fange; Krzystek, J et al. (2013) Diradical intermediate within the context of tryptophan tryptophylquinone biosynthesis. Proc Natl Acad Sci U S A 110:4569-73
Choi, Moonsung; Shin, Sooim; Davidson, Victor L (2012) Characterization of electron tunneling and hole hopping reactions between different forms of MauG and methylamine dehydrogenase within a natural protein complex. Biochemistry 51:6942-9
Davidson, Victor L; Liu, Aimin (2012) Tryptophan tryptophylquinone biosynthesis: a radical approach to posttranslational modification. Biochim Biophys Acta 1824:1299-305
Chen, Yan; Naik, Sunil G; Krzystek, J et al. (2012) Role of calcium in metalloenzymes: effects of calcium removal on the axial ligation geometry and magnetic properties of the catalytic diheme center in MauG. Biochemistry 51:1586-97
Abu Tarboush, Nafez; Shin, Sooim; Geng, Jiafeng et al. (2012) Effects of the loss of the axial tyrosine ligand of the low-spin heme of MauG on its physical properties and reactivity. FEBS Lett 586:4339-43

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