The members of the PII (GlnB) protein family are among the most broadly distributed regulatory proteins and are primarily involved in central nitrogen regulation in bacteria, archaea and in some plants. This protein family is biologically important not only for its distribution, but also for the critical roles that it has been shown to play in all aspects of nitrogen regulation and the balancing of carbon and nitrogen utilization. In the past few years, three very significant developments have occurred that this proposal seeks to take advantage of: The crystal structures of two members of this family have been solved, many organisms have been shown to have more than one homolog, and homologs in different organisms have been implicated in rather different biochemical functions. A critical issue, and a focus of this proposal, is the molecular basis of these different biochemical roles. This proposal will address this issue using our recent observation that Rhodospirillum rubrum has three homologs (named GlnB, GlnJ, and GlnK), with rather similar sequences, but with at least four different readily assayed functions in vivo. This provides an excellent model system for identifying functionally important residues in these homologs, correlating them with specific biological roles and eventually determining the specific receptor proteins that interact with the PII (GlnB) homologs in these roles. Identification of the critical regions of the PII homologs involved in different protein interactions will be of biological importance, especially when coupled with a better understanding of the proteins with which they interact. We cannot understand the diverse metabolic roles of the PII family until we have precisely this information. Only such information will, for example, explain the role of the post-translational uridylylation that is common among PII homologs. Given the extreme conservation of PII sequence across much of biology, it is a reasonable hypothesis that critical surfaces involved in the interactions of the PII homologs of R. rubrum will serve as important regions in other PII homologs as well

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM065891-03
Application #
6797741
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Program Officer
Anderson, James J
Project Start
2002-09-01
Project End
2006-08-31
Budget Start
2004-09-01
Budget End
2005-08-31
Support Year
3
Fiscal Year
2004
Total Cost
$196,425
Indirect Cost
Name
University of Wisconsin Madison
Department
Microbiology/Immun/Virology
Type
Schools of Earth Sciences/Natur
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
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Kerby, Robert L; Roberts, Gary P (2012) Burkholderia xenovorans RcoM(Bx)-1, a transcriptional regulator system for sensing low and persistent levels of carbon monoxide. J Bacteriol 194:5803-16
Wang, Di; Zhang, Yaoping; Pohlmann, Edward L et al. (2011) The poor growth of Rhodospirillum rubrum mutants lacking RubisCO is due to the accumulation of ribulose-1,5-bisphosphate. J Bacteriol 193:3293-303
Munk, A Christine; Copeland, Alex; Lucas, Susan et al. (2011) Complete genome sequence of Rhodospirillum rubrum type strain (S1). Stand Genomic Sci 4:293-302
Wang, Di; Zhang, Yaoping; Welch, Emily et al. (2010) Elimination of Rubisco alters the regulation of nitrogenase activity and increases hydrogen production in Rhodospirillum rubrum. Int J Hydrogen Energy 35:7377-7385
Zhang, Yaoping; Pohlmann, Edward L; Serate, Jose et al. (2010) Mutagenesis and functional characterization of the four domains of GlnD, a bifunctional nitrogen sensor protein. J Bacteriol 192:2711-21
Zhang, Yaoping; Pohlmann, Edward L; Roberts, Gary P (2009) Effect of perturbation of ATP level on the activity and regulation of nitrogenase in Rhodospirillum rubrum. J Bacteriol 191:5526-37
Zhu, Yu; Conrad, Mary C; Zhang, Yaoping et al. (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
Zhang, Yaoping; Wolfe, David M; Pohlmann, Edward L et al. (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, Yaoping; Pohlmann, Edward L; Conrad, Mary C et al. (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

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