Previous Article | Next Article ![]()
Journal of Bacteriology, June 2001, p. 3589-3596, Vol. 183, No. 12
Section of Microbiology, University of
California
Received 8 December 2000/Accepted 28 March 2001
The sdeK gene is essential to the Myxococcus
xanthus developmental process. We reported previously, based on
sequence analysis (A. G. Garza, J. S. Pollack, B. Z. Harris, A. Lee, I. M. Keseler, E. F. Licking, and M. Singer,
J. Bacteriol. 180:4628-4637, 1998), that SdeK appears to
be a histidine kinase. In the present study, we have conducted both
biochemical and genetic analyses to test the hypothesis that SdeK is a
histidine kinase. An SdeK fusion protein containing an N-terminal
polyhistidine tag (His-SdeK) displays the biochemical characteristics
of a histidine kinase. Furthermore, histidine 286 of SdeK, the putative
site of phosphorylation, is required for both in vitro and in vivo
protein activity. The results of these assays have led us to conclude
that SdeK is indeed a histidine kinase. The developmental phenotype of
a
0021-9193/01/$04.00+0 DOI: 10.1128/JB.183.12.3589-3596.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
SdeK, a Histidine Kinase Required for Myxococcus
xanthus Development
Davis, Davis, California 95616
sdeK1 strain could not be rescued by codevelopment
with wild-type cells, indicating that the defect is not due to the
mutant's inability to produce an extracellular signal. Furthermore,
the
sdeK1 mutant was found to produce both A- and
C-signal, based on A-factor and codevelopment assays with a
csgA mutant, respectively. The expression patterns of
several Tn5lacZ transcriptional fusions were examined in
the
sdeK1-null background, and we found that all
C-signal-dependent fusions assayed also required SdeK for full
expression. Our results indicate that SdeK is a histidine kinase that
is part of a signal transduction pathway which, in concert with the
C-signal transduction pathway, controls the activation of
developmental-gene expression required to progress past the
aggregation stage.
*
Corresponding author. Mailing address: Section of
Microbiology, University of California, Davis, One Shields Ave., Davis, CA 95616. Phone: (530) 752-9005. Fax: (530) 752-9014. E-mail: mhsinger{at}ucdavis.edu.
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 |