JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Schultz, A. C.
Right arrow Articles by Saxild, H. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Schultz, A. C.
Right arrow Articles by Saxild, H. H.

Journal of Bacteriology, June 2001, p. 3293-3302, Vol. 183, No. 11
0021-9193/01/$04.00+0   DOI: 10.1128/JB.183.11.3293-3302.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

Functional Analysis of 14 Genes That Constitute the Purine Catabolic Pathway in Bacillus subtilis and Evidence for a Novel Regulon Controlled by the PucR Transcription Activator

Anna C. Schultz,1 Per Nygaard,2 and Hans H. Saxild1,*

Section for Molecular Microbiology, BioCentrum-DTU, Technical University of Denmark, 2800 Lyngby,1 and Department of Biological Chemistry, University of Copenhagen, 1307 Copenhagen,2 Denmark

Received 6 December 2000/Accepted 2 March 2001

The soil bacterium Bacillus subtilis has developed a highly controlled system for the utilization of a diverse array of low-molecular-weight compounds as a nitrogen source when the preferred nitrogen sources, e.g., glutamate plus ammonia, are exhausted. We have identified such a system for the utilization of purines as nitrogen source in B. subtilis. Based on growth studies of strains with knockout mutations in genes, complemented with enzyme analysis, we could ascribe functions to 14 genes encoding enzymes or proteins of the purine degradation pathway. A functional xanthine dehydrogenase requires expression of five genes (pucA, pucB, pucC, pucD, and pucE). Uricase activity is encoded by the pucL and pucM genes, and a uric acid transport system is encoded by pucJ and pucK. Allantoinase is encoded by the pucH gene, and allantoin permease is encoded by the pucI gene. Allantoate amidohydrolase is encoded by pucF. In a pucR mutant, the level of expression was low for all genes tested, indicating that PucR is a positive regulator of puc gene expression. All 14 genes except pucI are located in a gene cluster at 284 to 285° on the chromosome and are contained in six transcription units, which are expressed when cells are grown with glutamate as the nitrogen source (limiting conditions), but not when grown on glutamate plus ammonia (excess conditions). Our data suggest that the 14 genes and the gde gene, encoding guanine deaminase, constitute a regulon controlled by the pucR gene product. Allantoic acid, allantoin, and uric acid were all found to function as effector molecules for PucR-dependent regulation of puc gene expression. When cells were grown in the presence of glutamate plus allantoin, a 3- to 10-fold increase in expression was seen for most of the genes. However, expression of the pucABCDE unit was decreased 16-fold, while expression of pucR was decreased 4-fold in the presence of allantoin. We have identified genes of the purine degradation pathway in B. subtilis and showed that their expression is subject to both general nitrogen catabolite control and pathway-specific control.

* Corresponding author. Mailing address: Section for Molecular Microbiology, BioCentrum-DTU, Technical University of Denmark, Building 301, 2800 Lyngby, Denmark. Phone: 45 25 24 95. Fax: 45 88 26 60. E-mail: hans.h.saxild{at}biocentrum.dtu.dk

Journal of Bacteriology, June 2001, p. 3293-3302, Vol. 183, No. 11
0021-9193/01/$04.00+0   DOI: 10.1128/JB.183.11.3293-3302.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2001 by the American Society for Microbiology. All rights reserved.