B.S., Chemistry, University of California (Berkeley) 1970 Ph.D., Molecular Biology, University of California (Berkeley) 1978 Postdoctoral Research: University of Wisconsin-Madison
Areas of Study
Genetics and biochemistry of nitrogen fixation and carbon monoxide oxidation
Awards
2000, UW Madison Vilas Associate
Research Papers
Kerby RL, Roberts GP (2012) Burkholderia xenovorans RcoM(Bx)-1, a transcriptional regulator system for sensing low and persistent levels of carbon monoxide. J. Bacteriol. 194(21):5803-16 (PMC3486110) · Pubmed
No abstract available.
Smith AT, Marvin KA, Freeman KM, Kerby RL, Roberts GP, Burstyn JN (2012) Identification of Cys94 as the distal ligand to the Fe(III) heme in the transcriptional regulator RcoM-2 from Burkholderia xenovorans. J. Biol. Inorg. Chem. 17(7):1071-82 (PMC3484680) · Pubmed
No abstract available.
Serate J, Roberts GP, Berg O, Youn H (2011) Ligand responses of Vfr, the virulence factor regulator from Pseudomonas aeruginosa. J. Bacteriol. 193(18):4859-68 (PMC3165676) · Pubmed
No abstract available.
Wang D, Zhang Y, Pohlmann EL, Li J, Roberts GP (2011) The poor growth of Rhodospirillum rubrum mutants lacking RubisCO is due to the accumulation of ribulose-1,5-bisphosphate. J. Bacteriol. 193(13):3293-303 (PMC3133260) · Pubmed
No abstract available.
Kerby RL, Roberts GP (2011) Sustaining N2-dependent growth in the presence of CO. J. Bacteriol. 193(3):774-7 (PMC3021221) · Pubmed
No abstract available.
Wang D, Zhang Y, Welch E, Li J, Roberts GP (2010) Elimination of Rubisco alters the regulation of nitrogenase activity and increases hydrogen production in Rhodospirillum rubrum. Int J Hydrogen Energy 35(14):7377-7385 (PMC2905822) · Pubmed
No abstract available.
Zhang Y, Pohlmann EL, Serate J, Conrad MC, Roberts GP (2010) Mutagenesis and functional characterization of the four domains of GlnD, a bifunctional nitrogen sensor protein. J. Bacteriol. 192(11):2711-21 (PMC2876476) · Pubmed
No abstract available.
Leduc JL, Roberts GP (2009) Cyclic di-GMP allosterically inhibits the CRP-like protein (Clp) of Xanthomonas axonopodis pv. citri. J. Bacteriol. 191(22):7121-2 (PMC2772467) · Pubmed
No abstract available.
Zhang Y, Pohlmann EL, Roberts GP (2009) Effect of perturbation of ATP level on the activity and regulation of nitrogenase in Rhodospirillum rubrum. J. Bacteriol. 191(17):5526-37 (PMC2725632) · Pubmed
No abstract available.
Zou X, Zhu Y, Pohlmann EL, Li J, Zhang Y, Roberts GP (2008) Identification and functional characterization of NifA variants that are independent of GlnB activation in the photosynthetic bacterium Rhodospirillum rubrum. Microbiology (Reading, Engl.) 154(Pt 9):2689-99 · Pubmed
No abstract available.
Marvin KA, Kerby RL, Youn H, Roberts GP, Burstyn JN (2008) The transcription regulator RcoM-2 from Burkholderia xenovorans is a cysteine-ligated hemoprotein that undergoes a redox-mediated ligand switch. Biochemistry 47(34):9016-28 (PMC2849662) · Pubmed
No abstract available.
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(13):4532-40 (PMC2446778) · Pubmed
No abstract available.
Kerby RL, Youn H, Roberts GP (2008) RcoM: a new single-component transcriptional regulator of CO metabolism in bacteria. J. Bacteriol. 190(9):3336-43 (PMC2347395) · Pubmed
No abstract available.
Wolfe DM, Zhang Y, Roberts GP (2007) Specificity and regulation of interaction between the PII and AmtB1 proteins in Rhodospirillum rubrum. J. Bacteriol. 189(19):6861-9 (PMC2045211) · Pubmed
No abstract available.
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(2):139-46 · Pubmed
No abstract available.
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 (Reading, Engl.) 152(Pt 7):2075-89 · Pubmed
No abstract available.
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(2):497-510 · Pubmed
No abstract available.
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(5):1866-74 (PMC1426566) · Pubmed
No abstract available.
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. U.S.A. 103(4):891-6 (PMC1347970) · Pubmed
No abstract available.
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. 281(2):1119-27 · Pubmed
No abstract available.
Ludden PW, Roberts GP (2005) Nitrogen fixation by photosynthetic bacteria. Photosyn. Res. 73(1-3):115-8 · Pubmed
No abstract available.
Reslewic S, Zhou S, Place M, Zhang Y, Briska A, Goldstein S, Churas C, Runnheim R, Forrest D, Lim A, Lapidus A, Han CS, Roberts GP, Schwartz DC (2005) Whole-genome shotgun optical mapping of Rhodospirillum rubrum. Appl. Environ. Microbiol. 71(9):5511-22 (PMC1214604) · Pubmed
No abstract available.
Zhang Y, Pohlmann EL, Roberts GP (2005) GlnD is essential for NifA activation, NtrB/NtrC-regulated gene expression, and posttranslational regulation of nitrogenase activity in the photosynthetic, nitrogen-fixing bacterium Rhodospirillum rubrum. J. Bacteriol. 187(4):1254-65 (PMC545621) · Pubmed
Puranik M, Nielsen SB, Youn H, Hvitved AN, Bourassa JL, Case MA, Tengroth C, Balakrishnan G, Thorsteinsson MV, Groves JT, McLendon GL, Roberts GP, Olson JS, Spiro TG (2004) Dynamics of carbon monoxide binding to CooA. J. Biol. Chem. 279(20):21096-108 · Pubmed
No abstract available.
Youn H, Kerby RL, Conrad M, Roberts GP (2004) Functionally critical elements of CooA-related CO sensors. J. Bacteriol. 186(5):1320-9 (PMC344431) · Pubmed
No abstract available.
Zhang Y, Pohlmann EL, Roberts GP (2004) Identification of critical residues in GlnB for its activation of NifA activity in the photosynthetic bacterium Rhodospirillum rubrum. Proc. Natl. Acad. Sci. U.S.A. 101(9):2782-7 (PMC365697) · Pubmed
No abstract available.
Kim K, Zhang Y, Roberts GP (2004) Characterization of altered regulation variants of dinitrogenase reductase-activating glycohydrolase from Rhodospirillum rubrum. FEBS Lett. 559(1-3):84-8 · Pubmed
No abstract available.
Youn H, Kerby RL, Roberts GP (2003) The role of the hydrophobic distal heme pocket of CooA in ligand sensing and response. J. Biol. Chem. 278(4):2333-40 · Pubmed
No abstract available.
Youn H, Kerby RL, Thorsteinsson MV, Clark RW, Burstyn JN, Roberts GP (2002) Analysis of the L116K variant of CooA, the heme-containing CO sensor, suggests the presence of an unusual heme ligand resulting in novel activity. J. Biol. Chem. 277(37):33616-23 · Pubmed
No abstract available.
Rubio LM, Rangaraj P, Homer MJ, Roberts GP, Ludden PW (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(16):14299-305 · Pubmed
No abstract available.
Zhang Y, Pohlmann EL, Ludden PW, Roberts GP (2001) Functional characterization of three GlnB homologs in the photosynthetic bacterium Rhodospirillum rubrum: roles in sensing ammonium and energy status. J. Bacteriol. 183(21):6159-68 (PMC100091) · Pubmed
No abstract available.
Antharavally BS, Poyner RR, Zhang Y, Roberts GP, Ludden PW (2001) Effects of specific amino acid substitutions on activities of dinitrogenase reductase-activating glycohydrolase from Rhodospirillum rubrum. J. Bacteriol. 183(19):5743-6 (PMC95467) · Pubmed
No abstract available.
Leduc J, Thorsteinsson MV, Gaal T, Roberts GP (2001) Mapping CooA.RNA polymerase interactions. Identification of activating regions 2 and 3 in CooA, the co-sensing transcriptional activator. J. Biol. Chem. 276(43):39968-73 · Pubmed
No abstract available.
Roberts GP, Thorsteinsson MV, Kerby RL, Lanzilotta WN, Poulos T (2001) CooA: a heme-containing regulatory protein that serves as a specific sensor of both carbon monoxide and redox state. Prog. Nucleic Acid Res. Mol. Biol. 67:35-63 · Pubmed
No abstract available.
Thorsteinsson MV, Kerby RL, Youn H, Conrad M, Serate J, Staples CR, Roberts GP (2001) Redox-mediated transcriptional activation in a CooA variant. J. Biol. Chem. 276(29):26807-13 · Pubmed
No abstract available.
Zhang Y, Pohlmann EL, Halbleib CM, Ludden PW, Roberts GP (2001) Effect of P(II) and its homolog GlnK on reversible ADP-ribosylation of dinitrogenase reductase by heterologous expression of the Rhodospirillum rubrum dinitrogenase reductase ADP-ribosyl transferase-dinitrogenase reductase-activating glycohydrolase regulatory system in Klebsiella pneumoniae. J. Bacteriol. 183(5):1610-20 (PMC95046) · Pubmed
No abstract available.
Thorsteinsson MV, Kerby RL, Conrad M, Youn H, Staples CR, Lanzilotta WN, Poulos TJ, Serate J, Roberts GP (2000) Characterization of variants altered at the N-terminal proline, a novel heme-axial ligand in CooA, the CO-sensing transcriptional activator. J. Biol. Chem. 275(50):39332-8 · Pubmed
No abstract available.
Thorsteinsson MV, Kerby RL, Roberts GP (2000) Altering the specificity of CooA, the carbon monoxide-sensing transcriptional activator: characterization of CooA variants that bind cyanide in the Fe(II) form with high affinity. Biochemistry 39(28):8284-90 · Pubmed
No abstract available.
Halbleib CM, Zhang Y, Roberts GP, Ludden PW (2000) Effects of perturbations of the nitrogenase electron transfer chain on reversible ADP-ribosylation of nitrogenase Fe protein in Klebsiella pneumoniae strains bearing the Rhodospirillum rubrum dra operon. J. Bacteriol. 182(13):3681-7 (PMC94538) · Pubmed
No abstract available.
Zhang Y, Pohlmann EL, Ludden PW, Roberts GP (2000) Mutagenesis and functional characterization of the glnB, glnA, and nifA genes from the photosynthetic bacterium Rhodospirillum rubrum. J. Bacteriol. 182(4):983-92 (PMC94374) · Pubmed
No abstract available.
Reynolds MF, Parks RB, Burstyn JN, Shelver D, Thorsteinsson MV, Kerby RL, Roberts GP, Vogel KM, Spiro TG (2000) Electronic absorption, EPR, and resonance raman spectroscopy of CooA, a CO-sensing transcription activator from R. rubrum, reveals a five-coordinate NO-heme. Biochemistry 39(2):388-96 · Pubmed
No abstract available.
Simon HM, Gosink MM, Roberts GP (1999) Importance of cis determinants and nitrogenase activity in regulated stability of the Klebsiella pneumoniae nitrogenase structural gene mRNA. J. Bacteriol. 181(12):3751-60 (PMC93853) · Pubmed
No abstract available.
Allen RM, Roll JT, Rangaraj P, Shah VK, Roberts GP, Ludden PW (1999) Incorporation of molybdenum into the iron-molybdenum cofactor of nitrogenase. J. Biol. Chem. 274(22):15869-74 · Pubmed
No abstract available.
Shah VK, Rangaraj P, Chatterjee R, Allen RM, Roll JT, Roberts GP, Ludden PW (1999) Requirement of NifX and other nif proteins for in vitro biosynthesis of the iron-molybdenum cofactor of nitrogenase. J. Bacteriol. 181(9):2797-801 (PMC93721) · Pubmed
No abstract available.
He Y, Gaal T, Karls R, Donohue TJ, Gourse RL, Roberts GP (1999) Transcription activation by CooA, the CO-sensing factor from Rhodospirillum rubrum. The interaction between CooA and the C-terminal domain of the alpha subunit of RNA polymerase. J. Biol. Chem. 274(16):10840-5 · Pubmed
No abstract available.
Vogel KM, Spiro TG, Shelver D, Thorsteinsson MV, Roberts GP (1999) Resonance Raman evidence for a novel charge relay activation mechanism of the CO-dependent heme protein transcription factor CooA. Biochemistry 38(9):2679-87 · Pubmed
No abstract available.
Shelver D, Thorsteinsson MV, Kerby RL, Chung SY, Roberts GP, Reynolds MF, Parks RB, Burstyn JN (1999) Identification of two important heme site residues (cysteine 75 and histidine 77) in CooA, the CO-sensing transcription factor of Rhodospirillum rubrum. Biochemistry 38(9):2669-78 · Pubmed
No abstract available.
Kim K, Zhang Y, Roberts GP (1999) Correlation of activity regulation and substrate recognition of the ADP-ribosyltransferase that regulates nitrogenase activity in Rhodospirillum rubrum. J. Bacteriol. 181(5):1698-702 (PMC93565) · Pubmed
No abstract available.
Goodwin PJ, Agar JN, Roll JT, Roberts GP, Johnson MK, Dean DR (1998) The Azotobacter vinelandii NifEN complex contains two identical [4Fe-4S] clusters. Biochemistry 37(29):10420-8 · Pubmed
No abstract available.
Spangler NJ, Meyers MR, Gierke KL, Kerby RL, Roberts GP, Ludden PW (1998) Substitution of valine for histidine 265 in carbon monoxide dehydrogenase from Rhodospirillum rubrum affects activity and spectroscopic states. J. Biol. Chem. 273(7):4059-64 · Pubmed
No abstract available.
Shelver D, Kerby RL, He Y, Roberts GP (1997) CooA, a CO-sensing transcription factor from Rhodospirillum rubrum, is a CO-binding heme protein. Proc. Natl. Acad. Sci. U.S.A. 94(21):11216-20 (PMC23420) · Pubmed
No abstract available.
Zhang Y, Burris RH, Ludden PW, Roberts GP (1997) Regulation of nitrogen fixation in Azospirillum brasilense. FEMS Microbiol. Lett. 152(2):195-204 · Pubmed
No abstract available.
Kerby RL, Ludden PW, Roberts GP (1997) In vivo nickel insertion into the carbon monoxide dehydrogenase of Rhodospirillum rubrum: molecular and physiological characterization of cooCTJ. J. Bacteriol. 179(7):2259-66 (PMC178962) · Pubmed
No abstract available.
Bintrim SB, Donohue TJ, Handelsman J, Roberts GP, Goodman RM (1997) Molecular phylogeny of Archaea from soil. Proc. Natl. Acad. Sci. U.S.A. 94(1):277-82 (PMC19314) · Pubmed
No abstract available.
Fox JD, He Y, Shelver D, Roberts GP, Ludden PW (1996) Characterization of the region encoding the CO-induced hydrogenase of Rhodospirillum rubrum. J. Bacteriol. 178(21):6200-8 (PMC178490) · Pubmed
No abstract available.
Simon HM, Homer MJ, Roberts GP (1996) Perturbation of nifT expression in Klebsiella pneumoniae has limited effect on nitrogen fixation. J. Bacteriol. 178(10):2975-7 (PMC178037) · Pubmed
No abstract available.
Zhang Y, Burris RH, Ludden PW, Roberts GP (1996) Presence of a second mechanism for the posttranslational regulation of nitrogenase activity in Azospirillum brasilense in response to ammonium. J. Bacteriol. 178(10):2948-53 (PMC178033) · Pubmed
No abstract available.
Davis R, Lehman L, Petrovich R, Shah VK, Roberts GP, Ludden PW (1996) Purification and characterization of the alternative nitrogenase from the photosynthetic bacterium Rhodospirillum rubrum. J. Bacteriol. 178(5):1445-50 (PMC177820) · Pubmed
No abstract available.
Fox JD, Kerby RL, Roberts GP, Ludden PW (1996) Characterization of the CO-induced, CO-tolerant hydrogenase from Rhodospirillum rubrum and the gene encoding the large subunit of the enzyme. J. Bacteriol. 178(6):1515-24 (PMC177833) · Pubmed
No abstract available.
He Y, Shelver D, Kerby RL, Roberts GP (1996) Characterization of a CO-responsive transcriptional activator from Rhodospirillum rubrum. J. Biol. Chem. 271(1):120-3 · Pubmed
No abstract available.
Homer MJ, Dean DR, Roberts GP (1995) Characterization of the gamma protein and its involvement in the metallocluster assembly and maturation of dinitrogenase from Azotobacter vinelandii. J. Biol. Chem. 270(42):24745-52 · Pubmed
No abstract available.
Zhang Y, Cummings AD, Burris RH, Ludden PW, Roberts GP (1995) Effect of an ntrBC mutation on the posttranslational regulation of nitrogenase activity in Rhodospirillum rubrum. J. Bacteriol. 177(18):5322-6 (PMC177326) · Pubmed
No abstract available.
Zhang Y, Burris RH, Ludden PW, Roberts GP (1995) Comparison studies of dinitrogenase reductase ADP-ribosyl transferase/dinitrogenase reductase activating glycohydrolase regulatory systems in Rhodospirillum rubrum and Azospirillum brasilense. J. Bacteriol. 177(9):2354-9 (PMC176891) · Pubmed
No abstract available.
Kerby RL, Ludden PW, Roberts GP (1995) Carbon monoxide-dependent growth of Rhodospirillum rubrum. J. Bacteriol. 177(8):2241-4 (PMC176875) · Pubmed
No abstract available.
Shelver D, Kerby RL, He Y, Roberts GP (1995) Carbon monoxide-induced activation of gene expression in Rhodospirillum rubrum requires the product of cooA, a member of the cyclic AMP receptor protein family of transcriptional regulators. J. Bacteriol. 177(8):2157-63 (PMC176861) · Pubmed
No abstract available.
Roll JT, Shah VK, Dean DR, Roberts GP (1995) Characteristics of NIFNE in Azotobacter vinelandii strains. Implications for the synthesis of the iron-molybdenum cofactor of dinitrogenase. J. Biol. Chem. 270(9):4432-7 · Pubmed
No abstract available.
Grunwald SK, Lies DP, Roberts GP, Ludden PW (1995) Posttranslational regulation of nitrogenase in Rhodospirillum rubrum strains overexpressing the regulatory enzymes dinitrogenase reductase ADP-ribosyltransferase and dinitrogenase reductase activating glycohydrolase. J. Bacteriol. 177(3):628-35 (PMC176637) · Pubmed
No abstract available.
Nielsen GM, Bao Y, Roberts GP, Ludden PW (1994) Purification and characterization of an oxygen-stable form of dinitrogenase reductase-activating glycohydrolase from Rhodospirillum rubrum. Biochem. J. 302 ( Pt 3:801-6 (PMC1137301) · Pubmed
No abstract available.
Zhang Y, Burris RH, Ludden PW, Roberts GP (1994) Posttranslational regulation of nitrogenase activity in Azospirillum brasilense ntrBC mutants: ammonium and anaerobic switch-off occurs through independent signal transduction pathways. J. Bacteriol. 176(18):5780-7 (PMC196782) · Pubmed
No abstract available.
Allen RM, Homer MJ, Chatterjee R, Ludden PW, Roberts GP, Shah VK (1993) Dinitrogenase reductase- and MgATP-dependent maturation of apodinitrogenase from Azotobacter vinelandii. J. Biol. Chem. 268(31):23670-4 · Pubmed
No abstract available.
Zhang Y, Burris RH, Ludden PW, Roberts GP (1993) Posttranslational regulation of nitrogenase activity by anaerobiosis and ammonium in Azospirillum brasilense. J. Bacteriol. 175(21):6781-8 (PMC206801) · Pubmed
No abstract available.
Burris RH, Roberts GP (1993) Biological nitrogen fixation. Annu. Rev. Nutr. 13:317-35 · Pubmed
No abstract available.
Homer MJ, Paustian TD, Shah VK, Roberts GP (1993) The nifY product of Klebsiella pneumoniae is associated with apodinitrogenase and dissociates upon activation with the iron-molybdenum cofactor. J. Bacteriol. 175(15):4907-10 (PMC204945) · Pubmed
No abstract available.
Pierrard J, Willison JC, Vignais PM, Gaspar JL, Ludden PW, Roberts GP (1993) Site-directed mutagenesis of the target arginine for ADP-ribosylation of nitrogenase component II in Rhodobacter capsulatus. Biochem. Biophys. Res. Commun. 192(3):1223-9 · Pubmed
No abstract available.
Pierrard J, Ludden PW, Roberts GP (1993) Posttranslational regulation of nitrogenase in Rhodobacter capsulatus: existence of two independent regulatory effects of ammonium. J. Bacteriol. 175(5):1358-66 (PMC193222) · Pubmed
No abstract available.
Kerby RL, Hong SS, Ensign SA, Coppoc LJ, Ludden PW, Roberts GP (1992) Genetic and physiological characterization of the Rhodospirillum rubrum carbon monoxide dehydrogenase system. J. Bacteriol. 174(16):5284-94 (PMC206364) · Pubmed
No abstract available.
Zhang Y, Burris RH, Roberts GP (1992) Cloning, sequencing, mutagenesis, and functional characterization of draT and draG genes from Azospirillum brasilense. J. Bacteriol. 174(10):3364-9 (PMC206006) · Pubmed
No abstract available.
Bao Y, Lies DP, Fu H, Roberts GP (1991) An improved Tn7-based system for the single-copy insertion of cloned genes into chromosomes of gram-negative bacteria. Gene 109(1):167-8 · Pubmed
No abstract available.
Liang JH, Nielsen GM, Lies DP, Burris RH, Roberts GP, Ludden PW (1991) Mutations in the draT and draG genes of Rhodospirillum rubrum result in loss of regulation of nitrogenase by reversible ADP-ribosylation. J. Bacteriol. 173(21):6903-9 (PMC209044) · Pubmed
No abstract available.
Lehman LJ, Roberts GP (1991) Glycine 100 in the dinitrogenase reductase of Rhodospirillum rubrum is required for nitrogen fixation but not for ADP-ribosylation. J. Bacteriol. 173(19):6159-61 (PMC208365) · Pubmed
No abstract available.
Lehman LJ, Roberts GP (1991) Identification of an alternative nitrogenase system in Rhodospirillum rubrum. J. Bacteriol. 173(18):5705-11 (PMC208301) · Pubmed
