UW-Madison Dept of Bacteriology

Select Publications

Leduc, J. L., and G. P. Roberts. 2009. Cyclic di-GMP Allosterically Inhibits the CRP-like Protein (Clp) of Xanthomonas axonopodis pv. citri. J. Bacteriol. 191: Jul 24. [Epub ahead of print]

Zhang, Y., E. L. Pohlmann, and G. P. Roberts. 2009. The effect of perturbation of ATP level on the activity and regulation of nitrogenase in Rhodospirillum rubrum. J. Bacteriol. 191:5526-5537.

Marvin, K. A., R. L. Kerby, H. Youn, G. P. Roberts, and J. N. Burstyn. 2008. The CO-activated transcription regulator RcoM-2 from Burkholderia xenovorans is a cysteine-ligated hemoprotein that undergoes a redox-mediated ligand switch. Biochemistry, 47: 9016-9028.

Zou, X., Y. Zhu, E. Pohlmann, J. Li, Y. Zhang, and G. P. Roberts. 2008. Identification and functional characterization of NifA variants that are independent of GlnB activation in the photosynthetic bacterium Rhodospirillum rubrum." Microbiology 154:2689-2699.

Reynolds, M.F., D. Shelver, K.M. Vogel, R. B. Parks, M.V. Thorsteinsson, R.L. Kerby, T.G. Spiro, G.P. Roberts, and J.N. Burstyn. 2000. Electronic absorption, EPR and resonance Raman spectroscopy of CO-sensing CooA reveals a five-coordinate NO-heme: Implications for the CO activation mechanism. Biochemistry 39:388-396.

Zhang, Y., E.L. Pohlmann, P.W. Ludden and G.P. Roberts. 2000. Mutagenesis and functional characterization of glnB, glnA and nifA genes from Rhodospirillum rubrum. J. Bacteriol. 182:983-992.

Thorsteinsson, M.V., R.L. Kerby, and G.P. Roberts. 2000. Altering the specificity of CooA, the CO-sensing transcriptional factor: characterization of CooA that bind cyanide in the FeII form with high affinity. Biochemistry 39: 8284-8290.

Halbleib, C., Y. Zhang, G. P. Roberts, and P.W. Ludden. 2000. Effects of perturbations of the nitrogenase electron transfer chain on the reversible ADP-ribosylation of nitrogenase Fe protein in Klebsiella pneumoniae strains bearing the Rhodospirillum rubrum dra operon. J. Bacteriol. 182:3681-3687.

Lanzilotta, W.N., D.J. Schuller, M.V. Thorsteinsson, R.L. Kerby, G.P. Roberts, and T.L. Poulos. 2000. Structure of the CO-sensing protein from Rhodospirillum rubrum: Insight into the mechanism of allosteric control in the CRP family of proteins. Nat. Struc. Biol. 7:876-880.

Zhang, Y, K. Kim, P.W. Ludden, and G.P. Roberts. 2001. Isolation and characterization of draT mutants that have altered the regulatory properties of dinitrogenase reductase ADP-ribosyl transferase in Rhodospirillum rubrum. Microbiology 147:193-202.

Thorsteinsson, M.V., R.L. Kerby, M. Conrad, H. Youn, C. R. Staples, W.N. Lanzilotta, T.J. Poulos, J. Serate, and G.P. Roberts. 2000. Characterization of variants altered at the N-terminal proline, a novel heme-axial ligand in CooA, the CO-sensing transcriptional factor. J. Biol. Chem. 276:39332-39338.

Roberts, G.P., M.V. Thorsteinsson, R. L. Kerby, W. N. Lanzilotta and T.L. Poulos. 2001. CooA, a heme-containing regulatory protein that serves as a specific sensor of both carbon monoxide and redox state. Prog. Nuc. Acid Res. Mol. Biol. 67:35-63.

Zhang, Y. E. Pohlman, C. Halbleib, P.W. Ludden and G.P. Roberts. 2001. Effect of PII and its paralogue GlnK on the reversible ADP-ribosylation of dinitrogenase reductase by heterologous expression of the Rhodospirillum rubrum DRAT-DRAG regulatory system in Klebsiella pneumoniae. J. Bacteriol. 183:1610-1620.

Thorsteinsson, M.V., R.L. Kerby, H. Youn, M. Conrad, J. Serate, C.R. Staples, and G. P. Roberts. 2001. Redox-mediated transcriptional activation in a CooA variant. J. Biol. Chem. 276:26807-26813.

Zhang, Y., E.L. Pohlmann, P.W. Ludden and G.P. Roberts. 2001. Functional characterization of three glnB homologs in the photosynthetic bacterium Rhodospirillum rubrum: their roles in sensing ammonium and energy status. J. Bacteriol. 183:6159-6168.

Leduc, J., M.V. Thorsteinsson, T. Gaal, and G.P. Roberts. 2001. Mapping CooA-RNA polymerase interactions: Identification of activating regions 2 & 3 in CooA, the CO-sensing transcriptional activator. J. Biol. Chem. 276:39968-39973.

Antharavally, B.S., R.P. Poyner, Y. Zhang, G.P. Roberts, and P.W. Ludden. 2001. Effects of specific amino acid substitutions on activities of dinitrogenase reductase-activating glycohydrolase from Rhodospirillum rubrum. J. Bacteriol. 183: 5743-5746.

Youn, H., R.L. Kerby, M.V. Thorsteinsson, M. Conrad, C.R. Staples, J. Serate, J. Beack, and G.P. Roberts. 2001. The heme pocket afforded by Gly117 is crucial for proper heme ligation and activity of CooA. J. Biol. Chem. 276: 41603-41610.

Rubio, L.M., R. Rangaraj, M.J. Homer, G.P. Roberts, and P.W. Ludden. 2002. Cloning and mutational analysis of the gamma gene from Azotobacter vinelandii defines a new family of proteins capable of metallocluster-binding and protein stabilization. J. Biol. Chem. 277:14299-14305.

Youn, H., R.L. Kerby, M.V. Thorsteinsson, M. Conrad, R.W. Clarke, J.N. Burstyn, and G.P. Roberts. 2002. Analysis of a variant of CooA , the heme-containing CO sensor, suggests the presence of an unusual heme ligand results in novel activity. J. Biol. Chem. 277:33616-33623.

Ludden, P.W., and G.P. Roberts. 2002. Nitrogen fixation by photosynthetic bacteria. Photo. Res. 73:115-118.

Kerby, R.L., H. Youn, M.V. Thorsteinsson, and G.P. Roberts. 2003. Repositioning about the dimer interface of the transcription regulator CooA: A major signal transduction pathway between the effector- and DNA-binding domains. J. Mol. Biol. 325:809-823.

Youn, H., R.L. Kerby, and G.P. Roberts. 2003. The role of the hydrophobic distal heme pocket of CooA in ligand sensing and response. J. Biol. Chem. 278:2333-2340.

Zhang, Y., E.L. Pohlmann, P.W. Ludden, and G.P. Roberts. 2003. Regulation of nitrogen fixation by multiple PII homologs in the photosynthetic bacterium Rhodospirillum rubrum. Symbiosis. 35:85-100.

Coyle, C.M., M. Puranik, H. Youn, S.B. Nielsen, R.D. Williams, R.L. Kerby, G.P. Roberts, and T.G. Spiro. 2003. Activation Mechanism of the CO Sensor CooA: Mutational and resonance Raman spectroscopic studies. J. Biol. Chem. 278:35384-35393.

Youn, H., R. L. Kerby, M. Conrad, and G. P. Roberts. 2004. Functionally critical elements of CooA-related CO sensors. J. Bacteriol. 186:1320-1329.

Zhang, Y., E. Pohlmann, and G.P. Roberts. 2004. Identification of critical residues in GlnB for its activation of NifA activity in photosynthetic bacterium Rhodospirillum rubrum. Proc. Natl. Acad. Sci. USA 101:2782-2787.

Kim, K. Y. Zhang, and G.P. Roberts. 2004. Characterization of altered-regulation variants of dinitrogenase reductase activating glycohydrolase from Rhodospirillum rubrum. FEBS Lett. 559:84-88.

Puranik, M., S. B. Nielsen, H. Youn, A. N. Hvitved, J. L. Bourassa, M. A. Case, C. Tengroth, G. Balakrishnan, M. V. Thorsteinsson, J. T. Groves, G. L. McLendon, G. P. Roberts, J. S. Olson, and T. G. Spiro. 2004. Dynamics of carbon monoxide binding to CooA. J. Biol. Chem. 279: 21096-21108.

Roberts, G. P., H. Youn, and R. L. Kerby. 2004. CO-sensing mechanisms throughout biology. Microbiol. Mol. Biol. Rev. 68:453-473.

Clark, R. W., H. Youn, R. B. Parks, M. M. Cherney, G. P. Roberts, and J. N. Burstyn. 2004. Investigation of the role of the N-terminal proline, the distal heme ligand in the CO-sensor CooA. Biochemistry 43:14149-14160.

Youn, H., R. L. Kerby and G.P. Roberts. 2004. Changing the ligand specificity of a highly specific heme-based sensor. J. Biol. Chem. 279:45744 - 45752.

Roberts, G. P., H. Youn, R. L. Kerby, and M. Conrad. 2005. CooA, a paradigm for gas sensing regulatory proteins. J. Inorg. Biochem. 99:280-292.

Zhang, Y., E. L. Pohlmann, and G. P. Roberts. 2005. GlnD is essential for NifA activation, NtrB/NtrC-regulated gene expression and the posttranslational regulation of nitrogenase activity in photosynthetic, nitrogen-fixing bacterium Rhodospirillum rubrum. J. Bacteriol. 187: 1254-1265.

Youn, H., M. V. Thorsteinsson, R. L. Kerby, M. Conrad, and G. P. Roberts. 2005. Dual roles of an E-helix residue, Glu167, in the transcriptional activator function of CooA. J. Bacteriol. 187:2573-2581.

Reslewic, S., S. Zhou, M. Place, Y. Zhang, A. Briska, S. Goldstein, C. Churas, R. Runnheim, D. Forrest, A. Lim, A. Lapidus, C. S. Han, G. P. Roberts, D. C. Schwartz. 2005. Whole-genome shotgun optical mapping of Rhodospirillum rubrum. Appl. Env. Microbiol. 71:5511-5522.

Youn H, Conrad M, Chung SY, Roberts GP. 2006. Roles of the heme and heme ligands in the activation of CooA, the CO-sensing transcriptional activator. Biochem. Biophys. Res. Commun. 348:345-50.

Ibrahim M, Kerby RL, Puranik M, Wasbotten IH, Youn H, Roberts GP, Spiro TG. 2006. Heme displacement mechanism of CooA activation: mutational and Raman spectroscopic evidence. J. Biol. Chem. 281:29165-73.

Zhang Y, Wolfe DM, Pohlmann EL, Conrad MC, Roberts GP. 2006. Effect of AmtB homologues on the post-translational regulation of nitrogenase activity in response to ammonium and energy signals in Rhodospirillum rubrum.
Microbiology.152:2075-89.

Zhang Y, Pohlmann EL, Conrad MC, Roberts GP. 2006. The poor growth of Rhodospirillum rubrum mutants lacking PII proteins is due to an excess of glutamine synthetase activity. Mol. Microbiol. 61:497-510.

Zhu Y, Conrad MC, Zhang Y, Roberts GP. 2006. Identification of Rhodospirillum rubrum GlnB variants that are altered in their ability to interact with different targets in response to nitrogen status signals. J. Bacteriol. 188:1866-74.

Clark RW, Lanz ND, Lee AJ, Kerby RL, Roberts GP, Burstyn JN. 2006. Unexpected NO-dependent DNA binding by the CooA homolog from Carboxydothermus hydrogenoformans. Proc. Natl. Acad. Sci. USA. 103:891-6.

Youn H, Kerby RL, Conrad M, Roberts GP. 2006. Study of highly constitutively active mutants suggests how cAMP activates cAMP receptor protein. J. Biol. Chem. 28:1119-27.

Ibrahim M, Kuchinskas M, Youn H, Kerby RL, Roberts GP, Poulos TL, Spiro TG. 2007. Mechanism of the CO-sensing heme protein CooA: new insights from the truncated heme domain and UVRR spectroscopy. J. Inorg. Biochem. 101:1776-85.

Wolfe DM, Zhang Y, Roberts GP. 2007. Specificity and regulation of interaction between the PII and AmtB1 proteins in Rhodospirillum rubrum. J. Bacteriol. 2007 189:6861-9.

Borjigin M, Li H, Lanz ND, Kerby RL, Roberts GP, Poulos TL. 2007. Structure-based hypothesis on the activation of the CO-sensing transcription factor CooA. Acta Crystallogr. D Biol. Crystallogr. 63:282-7.

Youn H, Kerby RL, Koh J, Roberts GP. 2007. A C-helix residue, Arg-123, has important roles in both the active and inactive forms of the cAMP receptor protein. J. Biol. Chem. 282:3632-9.

Clark RW, Youn H, Lee AJ, Roberts GP, Burstyn JN. 2007. DNA binding by an imidazole-sensing CooA variant is dependent on the heme redox state. J. Biol. Inorg. Chem. 12:139-46.

Youn H, Koh J, Roberts GP. 2008. Two-state allosteric modeling suggests protein equilibrium as an integral component for cyclic AMP (cAMP) specificity in the cAMP receptor protein of Escherichia coli. J. Bacteriol. 190:4532-40.

Kerby RL, Youn H, Roberts GP. 2008. RcoM: a new single-component transcriptional regulator of CO metabolism in bacteria. J. Bacteriol.190:3336-43.