Abstract

All of the enzymes in purine biosynthetic pathway, with the exception of the purB gene product, have been sequenced, overexpressed and the proteins purified to homogeneity. Using a combination of chemical and biosynthetic methods all the substrates in this pathway with the exception of the chemically unstable intermediate phosphoribosyl amine (PRA) can be obtained in modest amounts. These results set the stage for a variety of studies to be undertaken in the next funding period: (1) Genetic and kinetic methods will be utilized to investigate the importance of channeling of chemically unstable intermediates in the purine biosynthetic pathway, both in vivo and in vitro. (2) A variety of methods including rapid chemical quench kinetics and PIX will be utilized to investigate the mechanisms of a number of the enzymes involved in this pathway: PRPP-amidotransferase, GAR synthetase, FGAR-amidotransferase, AIR synthetase. (3) AIR carboxylase has been purified to homogeneity and in contrast to expectations based on genetic studies, is the purE gene product and not the gene product of both purE and purK. Attempts will be made to define the function of purK gene product.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM032191-10
Application #
3280801
Study Section
Biochemistry Study Section (BIO)
Project Start
1987-09-01
Project End
1995-06-30
Budget Start
1991-07-01
Budget End
1992-06-30
Support Year
10
Fiscal Year
1991
Total Cost
Indirect Cost

  Institution

Name
Massachusetts Institute of Technology
Department
Type
Schools of Arts and Sciences
DUNS #
City
Cambridge
State
MA
Country
United States
Zip Code
02139

  Publications

Morar, Mariya; Hoskins, Aaron A; Stubbe, JoAnne et al. (2008) Formylglycinamide ribonucleotide amidotransferase from Thermotoga maritima: structural insights into complex formation. Biochemistry 47:7816-30
Hoskins, Aaron A; Morar, Mariya; Kappock, T Joseph et al. (2007) N5-CAIR mutase: role of a CO2 binding site and substrate movement in catalysis. Biochemistry 46:2842-55
Anand, Ruchi; Hoskins, Aaron A; Stubbe, JoAnne et al. (2004) Domain organization of Salmonella typhimurium formylglycinamide ribonucleotide amidotransferase revealed by X-ray crystallography. Biochemistry 43:10328-42
Anand, Ruchi; Hoskins, Aaron A; Bennett, Eric M et al. (2004) A model for the Bacillus subtilis formylglycinamide ribonucleotide amidotransferase multiprotein complex. Biochemistry 43:10343-52
Hoskins, Aaron A; Anand, Ruchi; Ealick, Steven E et al. (2004) The formylglycinamide ribonucleotide amidotransferase complex from Bacillus subtilis: metabolite-mediated complex formation. Biochemistry 43:10314-27
Zilles, J L; Kappock, T J; Stubbe, J et al. (2001) Altered pathway routing in a class of Salmonella enterica serovar Typhimurium mutants defective in aminoimidazole ribonucleotide synthetase. J Bacteriol 183:2234-40
Kappock, T J; Ealick, S E; Stubbe, J (2000) Modular evolution of the purine biosynthetic pathway. Curr Opin Chem Biol 4:567-72
Mathews, I I; Kappock, T J; Stubbe, J et al. (1999) Crystal structure of Escherichia coli PurE, an unusual mutase in the purine biosynthetic pathway. Structure 7:1395-406
Thoden, J B; Kappock, T J; Stubbe, J et al. (1999) Three-dimensional structure of N5-carboxyaminoimidazole ribonucleotide synthetase: a member of the ATP grasp protein superfamily. Biochemistry 38:15480-92
Li, C; Kappock, T J; Stubbe, J et al. (1999) X-ray crystal structure of aminoimidazole ribonucleotide synthetase (PurM), from the Escherichia coli purine biosynthetic pathway at 2.5 A resolution. Structure 7:1155-66

Showing the most recent 10 out of 21 publications