Bacteria, fungi and plants recognize and respond to a multitude of environmental, metabolic and cell cycle signals through two-component signal transduction system and phosphorelays. These systems regulate a variety of genes and operons ranging from essential functions and virulence determinants to development and the ripening of fruit. Signal input activates an ATP-dependent autophosphorylation of a histidine residue of a kinase and signal propagation in these systems involves His-Asp phosphotransfer discovered, that of sporulation in bacteria, has been the subject of extensive genetic and biochemical studies. Structural analysis of the components of the pathway have shown how these signaling proteins interact and have given a first view of what residues determine specificity of molecular recognition. The objectives of the present proposal are to elucidate in detail the nature of molecular recognition, molecular specificity, and the mechanism of phosphotransfer in the phosphorelay using crystallographic techniques in conjunction with biochemical and genetic analyses. Two areas of focus will be the structure of the ultimate transcription factor, Spo0A, and its interaction with DNA and the structure of the signal-sensing histidine kinase that regulates phosphoryl input in the phosphorelay. The objective of this latter aim is to understand the mechanism by which signal ligand interaction activates kinase activity. Through these studies the complete mechanism of the pathway of signal transduction from signal ligand binding to gene activation will be understood.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM054246-06
Application #
6519749
Study Section
Molecular and Cellular Biophysics Study Section (BBCA)
Program Officer
Flicker, Paula F
Project Start
1997-01-01
Project End
2005-03-31
Budget Start
2002-04-01
Budget End
2003-03-31
Support Year
6
Fiscal Year
2002
Total Cost
$300,024
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Zhao, Haiyan; Volkov, Arsen; Veldore, Vidya Harini et al. (2010) Crystal structure of the transcriptional repressor PagR of Bacillus anthracis. Microbiology 156:385-91
Szurmant, Hendrik; Zhao, Haiyan; Mohan, Michael A et al. (2006) The crystal structure of YycH involved in the regulation of the essential YycFG two-component system in Bacillus subtilis reveals a novel tertiary structure. Protein Sci 15:929-34
Howell, Alistair; Dubrac, Sarah; Noone, David et al. (2006) Interactions between the YycFG and PhoPR two-component systems in Bacillus subtilis: the PhoR kinase phosphorylates the non-cognate YycF response regulator upon phosphate limitation. Mol Microbiol 59:1199-215
Varughese, Kottayil I; Tsigelny, Igor; Zhao, Haiyan (2006) The crystal structure of beryllofluoride Spo0F in complex with the phosphotransferase Spo0B represents a phosphotransfer pretransition state. J Bacteriol 188:4970-7
Varughese, Kottayil I (2005) Conformational changes of Spo0F along the phosphotransfer pathway. J Bacteriol 187:8221-7
Mukhopadhyay, Debashis; Varughese, Kottayil I (2005) A computational analysis on the specificity of interactions between histidine kinases and response regulators. J Biomol Struct Dyn 22:555-62
Vasudevan, Sona; Celikel, Reha; Ruggeri, Zaverio M et al. (2004) A single amino acid change in the binding pocket alters specificity of an anti-integrin antibody AP7.4 as revealed by its crystal structure. Blood Cells Mol Dis 32:176-81
Mukhopadhyay, Debashis; Sen, Udayaditya; Zapf, James et al. (2004) Metals in the sporulation phosphorelay: manganese binding by the response regulator Spo0F. Acta Crystallogr D Biol Crystallogr 60:638-45
Zhao, Haiyan; Bray, Tom; Ouellette, Marc et al. (2003) Structure of pteridine reductase (PTR1) from Leishmania tarentolae. Acta Crystallogr D Biol Crystallogr 59:1539-44
Varughese, Kottayil Iype (2002) Molecular recognition of bacterial phosphorelay proteins. Curr Opin Microbiol 5:142-8

Showing the most recent 10 out of 17 publications