Structure
and function studies of proteins that catalyze DNA
recombination. Biophysical investigations of DNA-binding and
zinc metalloproteins.
V(D)J recombination is a fundamental process in the development
of the immune system, as it leads to diversity of the
antigen-binding regions of T cell receptors and immunoglobulins.
In the V(D)J recombination reaction, gene segments are selected
and fused to produce the DNA sequence that encodes for the
variable regions of the antigen-binding receptors. This is a
site-specific recombination reaction where each gene segment is
flanked by a conserved recombination signal sequence (RSS). The
initial step in the reaction is cleavage at the border between a
coding gene segment and its flanking RSS. The macromolecular
assembly that carries out this site-specific cleavage is
referred to as the V(D)J recombinase, which consists of the
lymphoid-specific factors RAG1 and RAG2, proteins encoded by the
recombination-activating genes.
The
enzymatically-active macromolecular assembly is believed to
consist of RAG1 and RAG2 bound to two RSS signals forming a
synaptic complex, which is followed by coupled cleavage at the
border of each RSS. As the two RSS sites may be separated by up
to 106 bases in the genome, the topology of such an
assembly may be particularly intriguing. Examination of RAG1 and
RAG2 and their association in the V(D)J recombinase assembly
will provide insight into the molecular mechanism of V(D)J
recombination, as well as further our understanding of the
fundamental principles of protein-protein and protein-DNA
interactions. Current evidence shows that RAG1 and RAG2 are
multi-domain proteins. We have identified a novel zinc-binding
dimerization domain from residues 265-380 in the 1040 residue
murine RAG1 protein. This domain was characterized using a
combination of biophysical techniques, including X-ray
crystallography. In addition, RAG1 contains a catalytic 'core'
region from residues 384-1008. A core region of RAG2 has also
been identified from residues 1-387 of the 527 residue
full-length murine protein.
Current
research in my laboratory is to continue characterization of
domains in RAG1, as well as to determine the fundamental
protein-protein, protein-metal, and protein-DNA interactions
involved in formation of the V(D)J recombination assembly. To
accomplish these investigations a combination of biophysical
techniques are being used to quantify macromolecular
associations, study metal-binding properties, and determine
overall structural characteristics of the proteins and complexes
in solution. X-ray crystallographic studies will continue to be
used to gain information at atomic resolution.
Selected
Publications:
[Search Pubmed]
Godderz, L.J., Peak, M.M., and Rodgers, K.K. (2005)
Analysis of biological macromolecular assemblies using static
light scattering methods. Curr. Orig. Chem. 9:
899-908.
Godderz, L.J., and Rodgers, K.K. (2004) RAG1
oligomerization states and secondary structural properties: an
initial characterization of V(D)J recombinase complex formation.
Spectrosc. - Int. J. 18: 311-322.
De, P., and Rodgers, K.K. (2004) DNA cleavage
activity of the V(D)J recombination protein RAG1 is
autoregulated. Mol. Cell. Biol. 24:
6850-6860
De, P., and Rodgers, K.K. (2004) Putting the
pieces together: Identification and characterization of
structural domain in the V(D)J recombination protein RAG1.
Immunol. Rev. 200: 70-82.
Peak, M.M., Arbuckle, J.L., Rodgers, K.K., (2003) The central
domain of core RAG1 preferentially recognizes single-stranded RSS heptamer. J. Biol. Chem. 278: 18235-18240.
Godderz, L.J., Rahman, N.S., Risinger, G.M., Arbuckle, J.L., Rodgers, K.K.,
(2003) Self-association and conformational properties of RAG1:
Implications for formation of the V(D)J recombinase. Nucl.
Acids Res. 31: 2014-2023.
Arbuckle, J.L., Fauss,
L.J., Simpson, R., Ptaszek, L.M., Rodgers, K.K.,
(2001)
Identification of two topologically independent domains in RAG1
and their role in macromolecular interactions relevant to V(D)J
recombination. J. Biol. Chem. 276: 37093-37101.
Rodgers,
K.K., Villey, I.J., Ptaszek, L., Corbett, E., Schatz, D.G.,
and Coleman, J.E., (1999) A dimer of the lymphoid protein RAG1
recognizes the recombination signal sequence and the complex
stably incorporates the high mobility group protein HMG2. Nucleic
Acids Res. 27:2938-2946.
Junker,
M., Rodgers, K.K., and Coleman, J.E., (1998) Zinc as a
structural and folding element of proteins which interact with
DNA. Inorg. Chem. Acta. 275-276:481-492
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