Our group is interested in broad questions of molecualr recognition. We are investigating the folding and assembly of bacterial luciferase, a heterodimeric enzyme that catalyzes light emission in certain marine bacteria. We have demonstrated that formation of the native enzyme is kinetically determined, contrary to the generally accepted thermodynamic hypothesis of protein folding and stability. Currently, we are searching for amino acid residues that function during folding to direct structure formation but have no role in maintaining the structure of the native enzyme.
In a related project, we are investigating the regulation of the lux genes, which include the genes encoding luciferase, and have developed vectors based on quorum sensing for very high-level expression of foreign proteins in E. coli. Quorum sensing control systems in bacteria, which regulate such diverse biological phenomena as bioluminescence and pathogenesis, require a certain cell density, which is reported by a small molecule autoinducer, before a specific function is expressed. We are actively investigating how the presence of autoinducer is transduced into increased transcription of the lux regulon.
More details of these and other projects can be found on our laboratory
home page.
Any link on the below references will take you off
of the BMCB site and to an abstract of that particular paper.
Noland, B.W., and T.O. Baldwin. 2003. Demonstration of two independently
folding domains in the alpha subunit of bacterial luciferase by preferential
ligand binding-induced stabilization. Biochemistry 42: 3105-3112.
Inlow, J.K., and T.O. Baldwin. 2002. Mutational analysis of the subunit
interface of Vibrio harveyi bacterial luciferase. Biochemistry 41: 3906-3915.
Sparks, J.M., and T.O. Baldwin. 2001. Functional implications of the
unstructured loop in the (beta/alpha)(8) barrel structure of the bacterial
luciferase alpha subunit. Biochemistry 40: 15436-15443.
Apuy, J.L., X. Chen, D.H. Russell, T.O. Baldwin, and D.P. Giedroc.
2001. Ratiometric pulsed alkylation/mass spectrometry of the cysteine
pairs in individual zinc fingers of MRE-binding transcription factor-1
(MTF-1) as a probe of zinc chelate stability. Biochemistry 40: 15164-15175.
Apuy, J.L., Z-Y. Park, P.D. Swartz, L.J. Dangott, D.H. Russell, and
T.O. Baldwin. 2001. Pulsed-alkylation mass spectrometry for the study
of protein folding and dynamics: development and application to the
study of a folding/unfolding intermediate of bacterial luciferase. Biochemistry 40: 15153-15163.
Baldwin, T.O., and V.A. Green. 2000. Purification of firefly luciferase
from recombinant sources. Methods in Enzymology 305: 180-188.
Clark, A.C., B.W. Noland, and T.O. Baldwin. 2000. A rapid chromatographic
method to separate the subunits of bacterial luciferase in urea-containing
buffer. Methods in Enzymology 305: 157-164.
Baldwin, T.O., M.M. Ziegler, V.A. Green, and M.D. Thomas. 2000. Overexpression
of bacterial luciferase and purification from recombinant sources. Methods
in Enzymology 305: 135-152.
Fedorov, A.N., and T.O. Baldwin. 1999. Process of biosynthetic protein
folding determines the rapid formation of native structure. Journal
of Molecular Biology 294: 579-586.
Noland, B.W., L.J. Dangott, and T.O. Baldwin. 1999. Folding, stability
and physical properties of the alpha subunit of bacterial luciferase. Biochemistry 38: 16136-16145.
Baldwin, T.O. 1999. Protein folding in vivo: The importance of ribosomes. Nature
Cell Biology 1: E154-E155.
