Previous Article | Next Article ![]()
Journal of Bacteriology, September 1998, p. 4416-4425, Vol. 180, No. 17
Cetus Corporation, Emeryville, California
94608,1 and
Department of Biological
Chemistry, The Institute of Life Sciences, The Hebrew University of
Jerusalem, Jerusalem 91904, Israel2
Received 13 April 1998/Accepted 18 June 1998
Cyclic di-GMP (c-di-GMP) is the specific nucleotide regulator of
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Three cdg Operons Control Cellular Turnover of Cyclic
Di-GMP in Acetobacter xylinum: Genetic Organization and
Occurrence of Conserved Domains in Isoenzymes




-1,4-glucan (cellulose) synthase in Acetobacter
xylinum. The enzymes controlling turnover of c-di-GMP are
diguanylate cyclase (DGC), which catalyzes its formation, and
phosphodiesterase A (PDEA), which catalyzes its degradation. Following
biochemical purification of DGC and PDEA, genes
encoding isoforms of these enzymes have been isolated and found
to be located on three distinct yet highly homologous operons for
cyclic diguanylate, cdg1, cdg2, and
cdg3. Within each cdg operon, a
pdeA gene lies upstream of a dgc gene.
cdg1 contains two additional flanking genes,
cdg1a and cdg1d. cdg1a encodes a putative
transcriptional activator, similar to AadR of Rhodopseudomonas
palustris and FixK proteins of rhizobia. The deduced DGC and PDEA
proteins have an identical motif structure of two lengthy domains in
their C-terminal regions. These domains are also present in numerous
bacterial proteins of undefined function. The N termini of the DGC and
PDEA deduced proteins contain putative oxygen-sensing domains, based on
similarity to domains on bacterial NifL and FixL proteins,
respectively. Genetic disruption analyses demonstrated a physiological
hierarchy among the cdg operons, such that cdg1
contributes 80% of cellular DGC and PDEA activities and
cdg2 and cdg3 contribute 15 and 5%, respectively. Disruption of dgc genes markedly reduced in
vivo cellulose production, demonstrating that c-di-GMP controls this process.
*
Corresponding author. Mailing address: Department of
Biological Chemistry, The Institute of Life Sciences, The Hebrew
University of Jerusalem, Jerusalem 91904, Israel. Phone: 972-2-658 5430. Fax: 972-2-658 6448. E-mail:
benziman{at}vms.huji.ac.il.
Present address: Sunol Molecular Corporation, Miami, FL 33172.
Present address: Roche Molecular Systems, Emeryville, CA 94608.
§
Present address: Chiron Corporation, Emeryville, CA 94608.
Present address: Department of Agricultural Botany and the Otto
Warburg Center for Biotechnology in Agriculture, Faculty of Agriculture, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |