Previous Article | Next Article ![]()
J. Bacteriol., Apr 1997, 2651-2657, Vol 179, No. 8
TL Domanski, BL de Jonge and KW Bayles
The high level of cross-linking found in Staphylococcus aureus
peptidoglycan is dependent on the low-molecular-weight penicillin- binding
protein PBP4. Recently, the PBP4 gene, pbpD, was cloned and shown to be
adjacent to and divergently transcribed relative to the putative ABC-type
transporter gene, abcA. Disruption of abcA (in strain KB400) was previously
shown to result in heightened resistance to several antibiotics known to
interact with PBP4, suggesting that the regulation of pbpD is affected by
abcA. In this report, this hypothesis was confirmed by use of a Northern
(RNA) blot analysis which revealed increased accumulation of pbpD-specific
transcripts in KB400 compared to that in the wild-type strain, 8325-4. By
using reverse-phase high- performance liquid chromatography to examine the
structure of the peptidoglycan, it was demonstrated that the increased
expression of pbpD resulted in an increased level of peptidoglycan
cross-linking in the staphylococcal cell wall. Promoter fusion studies
demonstrated that the abcA mutation caused approximately 7-fold and
100-fold increases in pbpD and abcA promoter activities, respectively.
Primer extension experiments revealed that these genes have long,
untranslated leader sequences that result in a transcriptional overlap of
80 bp. Interestingly, deletion of a 26-bp region containing an inverted
repeat sequence resulted in the loss of expression from both the abcA and
the pbpD promoters. These data provide evidence that abcA and pbpD are
under the control of a common regulatory mechanism that may involve the
transport function of the abcA gene product.
Copyright © 1997, American Society for Microbiology
Transcription analysis of the Staphylococcus aureus gene encoding penicillin-binding protein 4
Program in Molecular and Cell Biology, University of Maryland, Baltimore County 21228, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»